1956 - Section 9 - Steering

SECTION 9 STEERING

CONTENTS OF THIS SECTION

Figure Index
Conventional Steering
Specifications
Power Steering
Assembly Manual

General Description

The regular production steering gear (fig. 1 and fig. 2) is the recirculating ball type with a gear ratio of 20:1. This same gear, which is also used in conjunction with the power steering unit, provides for ease of handling by having forces transmitted from worm to sector gear through ball bearings.

The principal working arrangement of the recirculating ball type steering gear consists of a "ball nut" connected to the steering worm and in mesh with the sector gear. Precision finished helical grooves inside the ball nut match helical grooves on the worm, and it is in these grooves that the ball bearings roll as the steering wheel is turned. There are two complete ball circuits within the ball nut. To keep the balls from running out of the end of either circuit, the nut is equipped with two tubular ball guides, each of which deflects the balls away from their helical path at one end of their travel, guides them diagonally across the back of the nut, and returns them to their helical path between the ball nut and the worm at the other end of their travel.

The balls within the helical path constitute a thread between the worm and ball nut, so that when the wormshaft is turned, the nut moves along the worm. At the same time, the balls roll freely between the worm and the ball nut, circulating within their closed circuits so that screw motion is obtained with rolling instead of sliding contact between parts.

Rugged rack teeth in that portion of the ball nut that faces the sector and the sector gear teeth are cut so as to provide true gear action between the sector and ball nut when the ball nut is located at a slight angle. This type of construction provides a means for backlash adjustment between the ball nut and the sector by shifting the sector shaft slightly along its own axis. This is accomplished by means of a convenient thrust screw, known as a lash adjuster.

The sector teeth are also cut so that when the sector is adjusted to take out all backlash at the center of travel or straight ahead position, there will be slight backlash at each end of travel. Thus snugness of the sector in the rack teeth in a straight ahead position can be obtained without sacrifice of perfect freedom at extreme positions, right or left, of the front wheels.

The sector shaft is straddle mounted in antifriction bushings and a grease seal is provided at the outer end of the shaft.

The worm is integrally welded to the mainshaft and is mounted between the ball bearings. The bearing at the end of the worm is adjustable for taking out end play in the wormshaft and for obtaining proper worm bearing load.

The steering wormshaft passes through a concentric mast jacket and shifter tube assembly (fig. 28 and fig. 29), which is secured to the instrument and dash panels but is not rigidly attached to the steering gear assembly. The shifter tube is free to rotate and slide within the mast jacket to transmit control forces from the shift lever to the transmission.

The steering linkage (fig. 3) is of the relay type, with the pitman arm connected to a relay rod through an adjustable ball and socket joint. The relay rod is connected to an idler arm which in turn, is connected to a support bolted to the frame side rail opposite the steering gear. Pivoting at the connections at each end of the idler arm is accomplished in rubber bushings. Connecting the relay rod to the steering arms are two adjustable tie rods with self adjusting ball and socket type joints (fig. 4)

Care Maintenance and Adjustments

LUBRICATION

The steering gear is filled at the factory with a special all-season gear lubricant. Seasonal change of this lubricant is unnecessary and the housing should not be drained. The steering gear lubricant level should be checked every lubrication period (1000 miles). Whenever required, additions should be made using a lubricant which, at low temperatures, is fluid and will not "channel" or cause hard steering and which will provide satisfactory lubrication under extreme summer conditions. Steering gear lubricants are marketed by many oil companies and either "Multi-Purpose" or "Universal" gear lubricants are satisfactory.

The steering gear linkage should be lubricated every 1000 miles, with chassis lubricant. Lubrication points and additional information on the chassis lubricant to be used can be found in Section 0 - General Lubrication.

ADJUSTMENTS

Steering-Gear

Before any adjustments are made to the steering gear in an attempt to correct such conditions as shimmy, loose or hard steering and road shocks, a careful check should be made of front end alignment, shock absorbers, wheel balance and tire pressure for possible causes.

Correct adjustment of steering gear is very important. While there are but two adjustments be made, the following procedure must be followed step-by-step in the order given.

Disconnect the steering relay rod from the pitman arm by removing cotter pin from end of relay rod, then removing end plug, spring, spring plug and ball seat (fig. 3 and fig. 5). Separate relay rod from pitman arm as shown in Figure 38, shifting steering linkage as required to obtain separation.
Loosen the pitman shaft lash adjuster screw lock nut and turn the adjuster screw (fig. 2) a few turns in a counterclockwise direction. This removes the load imposed on the worm bearings by the close meshing of rack and sector teeth. Turn steering wheel gently in one direction until stopped by gear, then back away about one turn. CAUTION: Do not turn steering wheel hard against stops when steering relay rod is disconnected as damage to ball guides may result.
Using J-544-A Steering Gear Checking Scale (fig. 6), measure pull at rim of wheel which is required to keep wheel in motion. This should be between 3/8 and pounds. NOTE: When making this check, it is important that the line of the scale be kept at right angles to the wheel spoke. If the pull necessary to move the wheel does not lie between the limits given above, adjustment of worm bearings is necessary.
To adjust worm bearings, loosen worm bearing adjuster lock nut and turn worm bearing adjuster shown in Figure 1 until there is no perceptible end play in worm. Check pull at wheel rim, readjusting if necessary to obtain proper pull. Tighten lock nut and recheck pull. If the gear feels "lumpy" after adjustment of worm bearings, there is probably damage in the bearings due to severe impact or to improper adjustment and the gear must be disassembled for replacement of damaged parts.
After proper adjustment of worm is obtained, and all mounting bolts securely tightened, adjust lash adjuster screw. First turn the steering wheel gently from one stop all the way to the other, carefully counting the total number of turns. Then turn wheel back exactly half way, to center position. Remove the steering wheel ornamental cap or horn button and the steering wheel retaining nut and washer. Note position of mark on end of wormshaft. This mark should be at top of shaft and aligned with mark on steering wheel (fig. 7). Turn lash adjuster screw clockwise to take out all lash in gear teeth, and tighten lock nut. Check pull at wheel rim with checking scale, taking highest reading of checking scale as wheel is turned through center position. This should be between 7/8 and 1 1/2 pounds. Readjust if necessary to obtain proper pull. NOTE: If 1 1/2 pounds is exceeded, turn lash adjuster screw counterclockwise, then come up on adjustment by turning the adjuster in a clockwise motion.
Tighten lock nut then recheck pull as it must lie between specified limits.
Reassemble relay rod to pitman arm and adjust as outlined below under Pitman Arm to Relay Rod Ball Joint. Replace steering wheel assembly.

Pitman Arm to Relay Rod Ball Joint

Remove cotter pin from end of relay rod, then using a drag link bit in end plug slot, tighten end plug until springs are compressed and plugs bottom (fig. 5).
Back off end plug 3/4 turn plus amount necessary to insert cotter pin, then insert pin.

Steering Wheel Alignment and High Point Centering

Remove steering wheel ornamental cap or horn button and wheel retaining nut. Set front wheels in straight ahead position. This can be checked by driving vehicle a short distance to determine steering wheel position at which vehicle follows a straight path.
With front wheels set straight ahead, check position of mark on end of wormshaft designating steering gear high point (fig. 7). This mark should be at the top of the shaft and aligned with mark on steering wheel. Remove steering wheel, if necessary, and align mark on wheel with mark on end of wormshaft. See Mast Jacket and Shifter Tube Removal for a description of the steering wheel removal operation.
If gear has been moved off high point when setting wheels in straight ahead position, loosen adjusting sleeve clamps on both left and right hand tie rods (fig. 3), then turn each sleeve an equal amount in the same direction to bring gear back on high point. CAUTION: Turning the sleeves an unequal number of turns or in different directions will disturb the toe-in setting of the wheels.
Tighten all sleeve clamp bolts.CAUTION: Tie rod clamp bosses must be below rods to avoid frame interference.

Mast Jacket and Steering Gear Alignment

Misalignment within the mast jacket assembly may cause steering or shifting interference (assuming the steering gear itself is in proper adjustment). A few basic causes of such interference together with suggested checks and adjustments are listed below.

Steering shaft not aligned with mast jacket and shifter tube assembly - Check and align steering shaft as described below under Mast Jacket - Steering Shaft Concentricity. Extreme cases of misalignment, preventing steering shaft from being centered in instrument panel opening without bending shaft, may be corrected as described under Steering Shaft Alignment.
Interference between steering wheel and top of direction signal housing - Check and adjust as described under Mast Jacket-Steering Wheel Clearance.
Damaged steering shaft, shifter tube or components within the mast jacket - See Major Service Operations.

Mast Jacket-Steering Shaft Eccentricity

With shift levers in neutral, slip cover and spring on steering shaft below adjusting ring towards steering gear box. Insert tool J-6041 (fig. 2) between steering shaft and adjusting ring. Holding tool handle at a point of contact bisecting keyway in adjusting ring, insert a 5/64 (.0781) drill rod or welding rod between steering shaft and tool J-6041 as shown in figure 1.
If shaft is not located properly, loosen the upper dash panel bracket clamp bolt and the two lower bracket retaining bolts ("fig. 3). Exerting slight pressure against 5/64 drill rod and tool J-6041, securely tighten first the upper bolt, then tighten the two lower bracket bolts.NOTE: The two nuts holding upper most jacket bracket to dash in passenger compartment must be tight before eccentricity adjustment is made.

STEERING SHAFT ALIGNMENT

Loosen the steering gear to frame bolts and the bolts securing the lower mast jacket bracket to the jacket and dash panel (fig. 9).
Install drill rods or shimming tool between steering shaft and adjusting ring to center shaft in mast jacket as described under Mast Jacket-Steering Shaft Concentricity.
Shim between steering gear and frame at bolt holes to maintain this alignment and tighten gear-to-frame and mast jacket bracket bolts. NOTE: The bracket upper clamp bolt should be tightened before the lower mast jacket bracket bolts.

MAST JACKET-STEERING WHEEL CLEARANCE

Measure gap between top. edge of direction signal housing and bottom outer edge of steering wheel shown in Figure 10. Clearance should be 1/32" - 9/64".
To adjust to proper clearance.
- Slide rubber seal on mast jacket (fig. 13) back from instrument panel and remove lower and upper chrome covers (fig. 11).
- Loosen clamp nuts at dash panel bracket and instrument panel (fig. 9 and fig. 12) just enough to permit mast jacket to be moved (without rotating) along steering shaft.
- Locate mast jacket to obtain 1/16" clearance at steering wheel and tighten clamp nuts at instrument panel, checking to see that key in clamp is located in keyway in mast jacket.
- Center mast jacket about steering shaft as described above under Mast Jacket Steering Shaft Concentricity and tighten all dash panel bracket bolts.
- Install upper and lower covers and slide rubber seal into position.

Toe-In Adjustment

A procedure for adjusting the steering linkage for proper toe-in setting is described in Section 3.

Major Service Operations

MAST JACKET AND SHIFTER TUBE REMOVAL

Disconnect all electrical connections and remove the back-up light switch, where installed, from mast jacket. NOTE: A combination back-up list neutral safety switch is installed on Powerglide models.
Remove two rubber cover upper fasteners from inside of dash panel at mast jacket opening.
Pry off horn button or ornamental cap and remove horn mechanism.
Slide rubber seal (fig. 13) away from covers, then remove lower cover retaining screw and washer and remove lower and upper covers (fig. 11).
On Powerglide models only:
- Disconnect ends of indicator rod from indicator lever and shifter tube and remove rod (fig. 13).
- Remove neutral safety switch.
- Remove transmission control selector plate shown in inset of Figure 9.
Remove steering wheel nut and washer from end of steering gear shaft, then using steering wheel puller J-2927-A, thread puller anchor screws into threaded holes provided in steering wheel hub. Turn center screw down against centering adapter (fig. 14) and force wheel from steering shaft. Remove spring and spring seat from end of steering shaft.
Remove nut, washers and clamp bolt from dash panel attaching bracket (fig. 9).
Disconnect transmission control linkage from shifter levers at swivels. Remove swivels from shifter levers.
Remove nuts and washers retaining clamp to bottom of instrument panel and remove clamp and rubber shims (fig. 12).
From inside vehicle pull mast jacket assembly carefully off steering shaft, rotating as necessary to clear dash clamp. Work shifter levers through dash seal by stretching the seal to clear levers. NOTE: It may be necessary to pry dash panel clamp apart to free the mast jacket.

STEERING GEAR REMOVAL

With mast jacket assembly removed, disconnect pitman arm from pitman shaft using Pitman Arm Puller J-5504 (fig. 15).
On Power Steering models remove the generator-to-support and generator brace bolts and move generator and pump assembly out of position (without disconnecting hoses) to obtain clearance to remove steering gear assembly.
Remove nuts and lockwashers from steering gear to frame bolts and remove bolts, shims where installed and steering gear.
Remove the four felt seals from mainshaft of steering gear assembly.

Steering Gear Overhaul

Steering Gear Disassembly As with any ball bearing unit the steering gear parts must be kept free of dirt. Clean paper or rags should be spread on the bench before starting disassembly of the steering gear. Refer to Figure 16.

Loosen lock nut on end of sector shaft and turn the lash adjuster a few turns counterclockwise (fig. 16). This will remove the load from the worm bearings caused by the close meshing of the rack and sector teeth.
Loosen the lock nut on the worm bearing adjuster shown in Figure 17 and turn the adjuster counterclockwise a few turns.
Place a pan under the assembly to catch the lubricant and remove the three bolts and washers attaching side cover to housing.
Pull the side cover with the sector and shaft from the housing (fig. 18). NOTE: If the sector does not clear the opening in the housing easily, turn the wormshaft by hand until the sector will pass through the opening in the housing.
Remove the worm bearing adjuster, adjuster lock nut and lower ball bearing from housing.
Draw wormshaft and nut assembly from housing (fig. 19). Remove upper ball bearing. CAUTION: Use care that the ball nut does not run down to either end of the worm. Damage will be done to the ends of the ball guides if the nut is allowed to rotate until stopped at the end of the worm.
Remove lock nut from lash adjuster and unscrew adjuster from side cover by turning adjuster clockwise. Slide adjuster and shim out of slot in end of sector shaft.
Remove sector shaft packing retainer; then remove and discard sector shaft packing.

Ball Nut Disassembly

As a rule, disassembly of the ball bearing nut will not be necessary if it is perfectly free with no indication of binding or tightness when rotated on the worm. However, if there is any indication of binding or tightness, the unit should be disassembled, cleaned and inspected as follows:

Remove screw and clamp retaining ball guides in nut. Draw guides out of nut (fig. 25).
Turn the nut upside down and rotate the wormshaft back and forth until all the balls have dropped out of the nut into a clean pan. With the balls removed the nut can be pulled endwise off the worm.

Inspection

With the steering gear completely disassembled (fig. 16) wash all parts in cleaning solvent. Dry them thoroughly with clean rags. With a magnifying glass inspect the ball bearings, bearing cups, worm and nut grooves and the surface of all balls for signs of indentation. Also check for any signs of chipping or breakdown of the surface.

Any parts that show signs of damage should be replaced. Balls must be replaced with genuine Chevrolet parts made according to specifications for this steering gear. No non-genuine balls should be used regardless of grade or quality. Inspect wormshaft seal for defects.

Inspect the sector shaft for wear and check the fit of the shaft in the housing bushings.

Inspect the fit of the pilot on the end of the sector shaft in its bushing in the side cover. If this bushing is worn, a new side cover and bushing assembly should be installed.

Check ball guides for damage at ends where they deflect or pick the balls from their helical path. Any damaged guides should be replaced.

Check steering gear wormshaft assembly for bent or damaged shaft.

Repairs

SECTOR SHAFT BUSHING REPLACEMENT

Support steering gear housing in an arbor press and press both sector shaft bushings from housing with Pitman Shaft Bushing Remover and Replacer J-1614, inserted from lower end of housing as shown (fig. 20).
Press new bushings into position from each end using the same sector shaft bushing driver as used for removal. NOTE: Service bushings are diamond bored to size and require no further reaming.

WORMSHAFT SEAL REPLACEMENT

If the wormshaft seal indicates need of replacement, it should be removed and a new seal pressed into position in the housing. Pitman Shaft Packing Retainer Installer J-5813 may be used to install seal.

SIDE COVER BUSHING REPLACEMENT

The entire side cover assembly, including bushing is serviced as a unit and should be replace where it is desired to replace the bushing.

SECTOR SHAFT PACKING REPLACEMENT

The sector shaft packing must be replaced each time a defective packing is indicated or the steering gear is disassembled. This operation is described under Steering Gear Assembly.

WORMSHAFT BEARING CUP REPLACEMENT

Remove wormshaft bearing cups using Wormshaft Bearing Cup Remover J-5822 with Slide Hammer J-2654A (fig. 21).
Press new bearing cups into position using Installer J-5755 (fig. 22).

Ball Nut Assembly

Place the wormshaft flat on the bench and slip the nut over the worm with the ball guide holes up and the shallow end of the rack teeth to the left from the steering wheel position. Align the grooves in the worm and nut by sighting through the ball guide holes.
Count 27 balls into a suitable container. This is the proper number of balls for one circuit. Drop counted balls from container into one of the guide holes while turning the worm gradually away from that hole. Continue until ball circuit is full from bottom of one guide hole to bottom of the other or until stopped by reaching the end of the worm. NOTE: In cases where the balls are stopped by the end of the worm, hold down those balls already dropped into the nut with the blunt end of a clean rod or punch (fig. 23) and turn the worm in the reverse direction a few turns. The filling of the circuit can then be continued. It may be necessary to work the worm back and forth, holding the balls down first in one hole then the other, to close up the spaces between the balls and fill the circuit completely and solidly.
Lay one-half of the ball guide, groove up, on the bench and place the remaining balls from the count container in it (fig. 24).
Close this half of guide with the other half. Hold the two halves together and plug each open end with Vaseline so balls will not drop out while installing guide.
Push the guide into the guide holes of the nut (fig. 25). This completes one circuit of balls. If the guide does not push all the way down easily, tap it lightly into place with the wooden handle of a screwdriver.
Fill second ball circuit in the same manner.
Assemble the ball guide clamp to the nut, being sure to use a lockwasher under the clamp screw, then tighten the screw securely.

Check the assembly by rotating the nut on the worm to see that it moves freely. Do not rotate the nut to the end of the worm threads as this may damage the ball guides. If there is any "stickiness" in the motion of the nut, some slight damage to the ends of the ball guides or to other gear components may have been overlooked.

Steering Gear Assembly

After a major service overhaul where all of the original factory installed lubricant has been washed out of the steering gear assembly, the threads of the adjuster, side cover bolts and lash adjuster should be coated with a suitable nondrying, oil resistant sealing compound such as Permatex No. 2. This is to prevent leakage of gear lubricant from the steering gear assembly. The compound should not be applied to female threads and extreme care should be exercised in applying this compound to the bearing adjuster, as the compound must be kept away from the wormshaft bearing. Also apply grease to the worm bearings, pitman shaft bushings, and ball nut teeth.

With wormshaft seal, bushings and bearing cups installed and ball nut assembly installed on wormshaft, slip upper ball bearing over wormshaft and insert wormshaft and nut assembly into housing, feeding end of shaft through upper ball bearing cup and seal (fig. 19).
Place ball bearing in adjuster cup and install adjuster and lock nut in lower end of housing.
Assemble the lash adjuster with shim in the slot in the end of sector shaft. Check the end clearance which should not be greater than .002" (fig. 26). For the purpose of adjusting this end clearance, a steering gear lash adjuster shim unit Part Number 605142 is available. It contains four shims-.063", .065", .067" and .069" thick.
After lash adjuster end clearance has been adjusted, start sector shaft pilot into bushing in side cover. Then, using a screwdriver through the hole in cover, turn lash adjuster in a counterclockwise direction to pull sector shaft pilot into its bushing as far as it will go.
Rotate wormshaft by hand until ball nut is about in the center of travel. This is to make sure that the rack and sector will engage properly, with center tooth of the sector entering center tooth space of the nut.
Place a new gasket on side cover, then push side cover assembly including sector shaft into place (fig. 18). After making sure there is some lash between rack and sector teeth, assemble and tighten side cover bolts.
Soak new sector shaft packing in engine oil to lubricate it; then install it in packing retainer. Use a new retainer if necessary.
Place Pitman Shaft Packing Protector J-5787 over end of sector shaft, then slide packing and retainer over protector and press into position with Installer J-5813 (fig. 27).

Adjustment on Bench

Tighten the worm bearing adjuster until all wormshaft end play has been removed. Then tighten the lock nut.
Install the steering wheel on the wormshaft temporarily. Carefully turn the steering wheel all the way in one direction and then turn back about one turn.
Using a J-544-A Steering Gear Checking Scale at right angles to one spoke at wheel rim, measure the pull required to keep the wheel in motion. This should be between 3/8 and 5/8 pounds. If necessary, adjust the worm bearing adjuster until proper pull is obtained.
Turn the steering wheel from one stop all the way to the other, counting the number of turns. Then turn the wheel back exactly half the number of turns to the center position and mark the wheel at the top or bottom.
Turn the sector lash adjuster screw (fig. 17) clockwise to remove all lash between rack and sector teeth. Tighten the lock nut. NOTE: Be sure adjustment is not changed while tightening the lock nut.
Using J-544-A Steering Gear Checking Scale, check pull at rim of steering wheel. Take highest reading on scale as wheel is pulled through center position. This should be between 7/8 and 1 1/2 pounds.
If necessary, readjust lash adjuster screw to obtain proper pull. Tighten lock nut to 10-15 ft. lbs. torque and again check pull.
Fill the assembly with steering gear lubricant to the level of the filler plug hole and replace filler plug.

Mast Jacket and Shifter Tube Overhaul

Disassembly

Refer to figure 28 and figure 29.

Slide rubber grommet back from lever support housing, drive out shift lever pin and remove shift lever and anti-rattle spring (fig. 30).
Remove single screw and clamp at location where wiring enters mast jacket.
Remove the three direction signal housing retaining screws indicated by arrows in Figure 31 and remove direction signal housing. It will be necessary to shift position of direction signal controls to gain access to the retaining screws. CAUTION: Withdraw housing with care to avoid damage to horn and direction signal wiring connections.
Remove locking plate and spacer washer (fig. 32).
Remove lever support housing (fig. 33).
Remove tanged washer (fig. 29) from mast jacket. This washer may have adhered to the lubriplate on bottom of lever support housing removed in step 5.
Reverse mast jacket and loosen retaining bolts on adjusting ring while holding ring to release compression of spring slowly. Remove adjusting ring. On Powerglide models remove spring from end of shifter tube.
On standard transmission models remove the two shifter levers and spacer from end of shifter tube assembly.
Remove shifter tube assembly by pulling it out from end of mast jacket.

Cleaning and Inspection

Clean all metal parts in cleaning solvent and dry them with compressed air.
Inspect transmission control lever housing for burrs, scratches and wear. NOTE: The clearance is critical between the shifter tube assembly and the lever support housing. There must be no interference between these two working parts and any excessive clearance must be corrected by the installation of new parts.
Inspect steering shaft bearing in direction signal housing. The bearing may be replaced by prying out of position and installing a new bearing and horn wire assembly.
Inspect direction signal wiring connections and switch.
Check direction signal lever for smoothness of operation and freedom from bind. Replace defective parts.
Inspect shifter levers and shifter tube assembly for worn or damaged parts. The shifter tube assembly must be replaced as a unit in event of worn or damaged component parts. NOTE: The shifter tube assembly on standard transmission models consists of the tube, spring, keys, felt seal and washers. On Powerglide models the shifter tube consists of an integral shifter lever and a felt seal.
On Powerglide models inspect indicator rod clip to see that it is anchored in the two holes in shifter tube and firmly clipped to the tube.

Assembly

On standard transmission models line up the lower key and washer tang of the shifter tube assembly (fig. 34).
Generously lubriplate all keys and small diameter ends of the shifter tube.
Insert shifter tube into mast jacket from lower end of mast jacket. On standard transmission models, align washer tang in slot provided in mast jacket (fig. 34). On Powerglide models install return spring to lower end of shifter tube and slide against shifter lever.
On standard transmission models only:
- Lubriplate and install second and third shifter lever on shifter tube. A "U" is stamped on this lever for identification.
- Lubriplate and install spacer on tube with ramped edge away from shifter lever.
- Lubriplate and install first and reverse lever on shifter tube. An "L" is stamped on this lever for identification purposes.
Lubriplate and place adjusting ring in lower end of mast jacket over shifter tube.
- Apply sufficient load on the adjusting ring parallel to the centerline of the shifter tube. Tighten the three screws holding adjusting ring to bottom of mast jacket. This will maintain a tight fit between levers and adjusting ring.NOTE: It is necessary to maintain tight fit on installation due to slight wear on washer between shift levers caused by constant use of shift levers.
- On Powerglide models, push adjusting ring into mast jacket bolt slots as far as possible to compress the return spring, then tighten the three adjusting ring bolts.
Reverse mast jacket and working from the top end install tanged washer (fig. 29), resting it on the three tabs protruding inward and keyed in the slot provided in the jacket.
Lubriplate inner diameter of lever support housing and install housing, fitting keyway in housing over key on shifter tube (fig. 33).
Carefully feed direction signal and horn wires through lever support housing and into wiring opening at upper end of the mast jacket, then down through mast jacket and out lower wiring opening. NOTE: The use of a leader wire, first passed between the mast jacket and shifter tube and through each opening, then secured to the wire ends, will facilitate this operation. Lift lever support housing off most jacket and shifter tube as required to gain access to upper wiring opening in mast jacket.
With lever support housing installed, install spacer washer and locking plate in bayonet slots in mast jacket. Place direction signal housing in normally installed position on mast jacket to check alignment of attaching screw holes in housing and locking plate.
Install direction signal housing retaining screws, locating key in housing in mast jacket keyway.
Check end play between lever support housing and direction signal housing. End play should be .004"-.009". If not within specified range, remove direction signal housing and locking plate, then install proper size spacer washer to give .004"-.009" end play. Reinstall locking plate and direction signal housing and recheck end play. NOTE: Four thicknesses of spacer washers (.035", .039", .043", .047") are available, with the largest washer identified by a single notch or drilled hole, next largest by two notches or drilled holes, etc.
Lubriplate the anti-rattle spring and place it on end of shift lever, then position shift lever in housing and install pin. Slide rubber grommet into position over pin and against housing.
Install wiring clamp over opening where wiring enters mast jacket.

Steering Gear Installation

Place the four felt seals over mainshaft and slide against steering gear housing.
Insert end of mainshaft through dash panel opening and position steering gear assembly on frame. Install bolts, lockwashers and nuts through bracket. NOTE: Shims may be placed between steering gear and frame as required to center steering shaft in instrument panel opening.
Connect pitman arm to pitman shaft.
Install mast jacket and shifter tube assembly as described below. Also install generator and pump assembly on Power Steering models.

MAST JACKET AND SHIFTER TUBE INSTALLATION

Slip assembled mast jacket over steering shaft and feed it downward to approximate location, rotating as required to provide clearance for the shifter levers and other projections at dash panel and dash panel clamp. The rubber seal at the dash panel opening must be stretched to clear shifter levers.
Position upper mast jacket clamp with upper and lower rubber shims installed (fig. 12) over retaining bolts so that key in clamp engages keyway in bottom of mast jacket and clamp is centered in instrument panel opening. Install clamp washers and nuts and tighten nuts just enough to-hold key in keyway (to prevent rotation of mast jacket) and still permit mast jacket to be moved along steering shaft.
Install steering wheel, horn mechanism and horn button or ornamental cap, aligning steering wheel with mark on end of steering shaft.
Grasp mast jacket assembly and pull assembly back along steering shaft toward steering wheel. Locate assembly 1/16" from steering wheel by placing feeler gauge or 1/16" shim stock between top edge of direction signal housing and bottom outer edge of steering wheel (shown in Figure 10). With assembly located in this position, tighten clamp nuts below instrument panel.
Install dash panel attaching bracket clamp bolt, washers and nut.
With shift levers in neutral, insert Chevrolet tool J-6041 (fig. 2) and follow instructions as described under "Mast Jacket Steering Shaft Eccentricity" previously in this manual.
Connect transmission control rods to shifter levers. On Powerglide models install the transmission control selector plate shown in the inset of Figure 9.
With shift lever in Neutral position install back-up light and neutral safety switch where applicable.
Position rubber seal and cover to dash panel and install upper fasteners.
Connect horn wire and, where applicable, direction signal, back-up light and neutral safety switch wiring, by connecting matching colors at the connectors. CAUTION: Where equipped with a combination back-up light neutral safety switch, it is imperative that wires be connected to proper switch terminals as illustrated in Figure 36.
After completing installation, check steering and shifting for bind. Also check neutral safety and back-up light switch, where applicable for proper operation. It may be necessary to loosen the neutral safety switch attaching screws and shift position of switch to obtain proper operation.

Steering Linkage Overhaul

Tie Rods

There are two tie rods used on all model passenger cars. Each tie rod is of three piece construction, consisting of the tie rod and two tie rod end assemblies. The ends are threaded into the rod and locked with clamps. Right and left hand threads are provided to facilitate toe-in adjustment and steering gear centering.

The tie rod ends used (fig. 4) are self adjusting for wear and require no attention in service other than periodic lubrication and occasional inspection to see that ball studs are tight. Replacement of tie rod ends should be made when excessive up and down motion is evident or if any lost motion or end play at ball end of stud exists.

Removal

Remove cotter pins from ball studs and remove castellated nuts.
To remove outer ball stud, tap on steering arm at tie rod end with a hammer while using a heavy hammer or similar tool as a backing (fig. 37). If necessary pull downward on tie rod to remove from steering arm.
Remove inner ball stud from relay rod, using same procedure as described in Step 2.
To remove tie rod ends from tie rods, loosen clamp bolts and unscrew end assemblies.

Installation

If tie rod ends were removed, install ends on tie rod making sure both ends are threaded an equal distance into the tie rod.
Make sure that threads on ball studs and in ball stud nuts are perfectly clean and smooth. Install neoprene seals on ball studs. NOTE: If threads are not clean and smooth, ball studs may turn in tie rod ends when attempting to tighten nut.
Install ball studs in steering arms and relay rod.
Install ball stud nuts, tighten securely and install cotter pins. Lubricate tie rod ends.
Adjust toe-in as described in Section 3. NOTE: Before locking clamp bolts on tie rods, make sure that the tie rod ends are in alignment with their ball studs (each ball joint is in the center of its travel). If the tie rod is not in alignment with the studs, binding will result. Also, tie rod clamp bosses must be below tie rods to avoid frame interference.

Relay Rod

Removal

Remove inner ends of tie rods from relay rod as described under Tie Rod-Removal.
Remove cotter pin from end of relay rod at pitman arm ball stud attachment.
Using a drag link bit, remove end plug from socket and remove spring plug and outer ball seat from relay rod (fig. 5).
Detach relay rod from pitman arm (fig. 38) and remove inner ball seat, plug and spring from relay rod (fig. 5). Shift steering linkage as required to free pitman arm from relay rod.
Remove cover and seal from pitman arm.
Remove cotter pin and nut from relay rod end of idler arm.
Remove relay rod from vehicle.

Cleaning and Inspection

Remove accumulated grease and dirt from assembly and inspect for damage or excessive wear.

Repairs

Pitman arm ball seats may be replaced if inspection shows necessity.

The Idler Arm to Relay Rod bushing may be replaced by pressing out old bushing and pressing in new bushing. Note side of rod which bushing shoulder is against and install new bushing in same manner.

Installation

With wheels in a straight ahead position, place relay rod over idler arm, then install and tighten nut to 70 ft. lbs. Advance nut just enough to align castellation with cotter pin hole and install pin.
Install new seal and cover over ball at end of pitman arm.
Install inner spring, plug and seat to pitman arm end of relay rod.
Raise end of rod and install on pitman arm.
Install outer ball seat, spring, plug and end plug.
Tighten end plug until springs are compressed and plugs bottom, then back off 3/4 turn plus amount necessary to insert cotter pin. Insert cotter pin to lock adjustment.
Install tie rod ends to relay rod as previously described under Tie Rods.
Lubricate tie rod ends and pitman arm to relay rod ball joint.
Adjust toe-in (see Section 3) and align steering wheel as described previously in this section under Steering Wheel Alignment and High Point Centering.

Idler Arm

Removal

Remove cotter pins and nuts from ends of idler arm and remove relay rod from idler arm.
Remove idler arm from idler arm bracket. Cleaning and Inspection Remove accumulated grease and dirt from assembly and inspect for damage or excessive wear.

Cleaning and Inspection

Remove accumulated grease and dirt from assembly and inspect for damage or excessive wear.

Repairs

If inspection shows a faulty bushing, press out old bushing and press in new bushing.

Installation

Position idler arm over idler arm bracket and install nut but do not tighten.
Install relay rod to idler arm and install nut but do not tighten.
With wheels in straight ahead position and steering gear on high point, tighten idler arm to bracket nut and relay rod to idler arm nut to 70 ft. lbs. Advance both nuts just enough to align castellations with cotter pin holes and install pins.

Troubles and Remedies

Symptom and Probable Cause
Probable Remedy

Hard Steering

a. Lack of lubrication.
a. Lubricate steering gear, tie rod ends, steering relay rod ball joints and steering knuckle joints.

b. Pitman shaft to relay rod ball joint
b. Readjust ball joint.

c. Underinflated tires.
c. Inflate tires to recommended pressure.

d. Improper adjustment.
d. Adjust according to instruction.

e. Interference between steering shaft and mast jacket assembly caused by misalignment,
bent steering shaft or damaged parts within the mast jacket assembly.
e. Adjust or replace parts as required.

Loose Steering

a. Improper adjustments.
a. Adjust according to instructions.

b. Loose pitman shaft to relay rod ball joint.
b. Adjust ball joint.

c. Worn steering knuckle ball joints.
c. Replace steering knuckle ball joints.

d. Worn pitman shaft bushings.
d. Replace bushings.

Specifications

Gear Ratio - 20:1
Type - Recirculating Ball
Number Balls Used - 54
Lash Adjustment or High Point - 7/8 to 1 1/2 lbs.
End Clearance-Lash Adjuster to Sector Slot - 002" max.
Worm Bearing Adjustment - 3/8 to 5/8 lbs. to keep wheel in motion

Power Steering System

Index

Figure Index for Power Steering Only
Description and Operation
Power Steering Generator
Recirculating Ball
Hydraulic Steering Mechanism
Hydraulic Pump and Reservoir
Hydraulic Steering Maintenance
Care, Maintenance and Adjustments
Fluid Level
Bleeding Hydraulic System
Pump Belt Tension
Checking Pump Pressure
Steering Wheel Alignment
Major Service Operations
Reservoir and Pump Assembly
Removal
Disassembly
Cleaning and Inspection
Assembly
Control Valve
Removal and Disassembly
Cleaning and Inspection
Assembly
Power Cylinder
Removal
Inspection
Seal Replacement
Trouble Diagnosis
Hard Steering
Excessive Play or Looseness in Steering Mechanism
Low Oil Pressure
Poor Centering or Recovery on Turns
Oil Leaks
Figure Index for Power Steering Only

Fig. 40 - Hydraulic Steering System
Fig. 41 - Control Valve Adapter Assembly
Fig. 42 - Control Valve Connections
Fig. 43 - Hydraulic Pump and Reservoir Mounted to Generator (8 Cyl. Engine)
Fig. 44 - Checking Fluid Level
Fig. 45 - Drain Fluid from Reservoir
Fig. 46 - Removing Hydraulic Pump
Fig. 47 - Hydraulic Pump Assembly
Fig. 48 - Control Valve Removal
Fig. 49 - Unscrew Control Valve
Fig. 50 - Control Valve Disassembled
Fig. 51 - Control Valve Installation
Fig. 52 - Power Cylinder Installation
Fig. 53 - Power Cylinder
Fig. 54 - Power Steering Special Tools

General Description

Chevrolet Power Steering equipment on passenger cars, consists of a recirculating ball type steering gear and linkage to which a hydraulic power mechanism has been added as part of the steering linkage. The hydraulic mechanism furnishes additional power to ASSIST the manual operation so that the turning effort at the steering wheel is greatly reduced.

The power steering equipment is designed to reduce steering effort but not to remove the so called "feel" of steering. With Chevrolet Power Steering, the hydraulic assistance is zero up to a pull of about 3 pounds at the rim of the steering wheel and the steering of the car is entirely normal. At this 3 pound load, the hydraulic system starts to assist the driver's effort and from 3 to 8 pounds pull, the input effort is proportional to the force necessary to turn the front wheels. The 8 pound load is sufficient to turn the front wheels with the car standing still which means the hydraulic system is doing about 80% of the work of steering.

In addition to assisting the driver in steering the car, Power Steering greatly reduces the effort required in parking. The oil filled hydraulic cylinder absorbs road shocks when driving over rough roads, railroad tracks, etc. This permits the wheel in the driver's, hand to remain steady, reduces driver "fatigue" and permits many miles of driving without tiring.

POWER STEERING GENERATOR

A special generator is used with new cars equipped with power steering. On these models, the power steering pump is mounted on the commutator end frame and is driven by the splined armature shaft which extends from the generator.

Generators of this type use ball bearings at both end frames and all parts have close tolerances in order to provide for the proper alignment between the generator and the power steering pump. Improper alignment of the generator and power steering pump may cause a noisy generator and pump assembly. Improper alignment may result from careless handling of the generator assembly (resulting in deformed parts), worn bearings, careless assembly of the pump to the generator, or other similar items.

Power steering pumps are sealed to prevent leakage of fluid. One of the seals used for this purpose mounts on the polished surface (1/2" diameter) of the generator shaft extension. Damage to this surface (which is machined to very close limits) or damage to the seals during reassembly of the pump to the generator may result in loss of fluid from the power steering pump.

Lubrication required on the generator is the same as for the standard installation.

Recirculating Ball

The steering gear used with Power Steering is the same recirculating ball type as used on regular production jobs.

HYDRAULIC STEERING MECHANISM

The hydraulic power steering mechanism consists of an engine driven oil pump delivering oil at a pressure of 750 pounds per square inch, an oil reservoir, a double-acting hydraulic power cylinder, and a control valve (fig. 40).

The hydraulic power cylinder assembly is mounted on a bracket on the relay rod at one end and to another bracket on the frame of the vehicle.

HYDRAULIC CONTROL VALVE

The hydraulic control valve is attached to the left end of the steering relay rod (fig. 40) and is operated by the pitman arm in the following manner:

The pitman arm ball stud is retained in a sliding bearing sleeve inside the steering linkage tube. Protruding from the ball seat adjusting nut is a long valve shaft (fig. 41). The spool of the control valve is attached to this shaft so that any movement of the sliding bearing sleeve is transmitted to the control valve spool. The spool is restricted to a movement of .050" travel to the right and left from its centered position by a spacer between the control valve housing and adapter housing and by the correct adjustment of the ball stud adjuster. A steel pin (fig. 41) locks the ball stud adjuster to the sliding bearing sleeve. The spool assembly has two annular grooves which connect three annular passages inside the valve housing. The valve spool member is centered and restrained from actuation on the valve shaft by a pre-loaded spring. It is necessary to overcome the pre-loaded of the spring before the valve spool can be moved in either direction. When there is sufficient resistance to rotation of the steering arm developed at the front wheels, continued turning of the steering wheel will result in an axial movement of the valve shaft, thus overcoming the pre-load of the spring. This axial movement is due to the hook-up from the pitman arm (fig. 42). When the valve spool assembly is in the centered position, the oil from the hydraulic pump flows through the center passage of the valve body, through the annular grooves in the spool to the annular passages in the housing and then back to the pump.

When axial movement of the spools occurs with a three pound effort on the steering wheel, the direct circuit of the pump is interrupted by shutting off both of the direct return passages. The oil is then forced to travel to one end of the hydraulic power cylinder to move the cylinder axially on the piston shaft. At the same time the opposite end of the power cylinder is open to the pump return line and permits oil at this end to return through the control valve to the pump reservoir.

Hydraulic Pump and Reservoir

The oil pump, a vane type pump, is mounted on the engine in position to be driven by a splined extension of the generator armature shaft (fig. 43).

The pump houses a serrated driving hub or rotor in which ten vanes slide radially outward to contact the hardened and ground inside surface of a cam ring. As the shaft and rotor rotate, centrifugal force and fluid pressure against the inner ends causes the vanes to follow the cam contour of the ring. The contour of the ring is so shaped that two opposing pumping chambers are formed. In each pumping chamber, the increasing and decreasing pockets formed between the rotor, vanes, and ring, propel the oil from the entrance to the exit ports of the pump.

The pump contains a combination overload relief valve, which is set to open at 750-P.S.I. at 170°F and a flow control valve which recirculates oil within the pump as required to regulate the output volume between 1.1 gal. per minute at idling speed to 1.8 gal. per minute at approximately 3600 RPM.

The reservoir encloses the pump cover assy. (fig. 43) and provides a reserve supply of oil to assure complete filling of the hydraulic system. An air chamber in the upper part of the reservoir and a vented cover attachment provide for the escape of any air that may be introduced into the system.

HYDRAULIC STEERING MAINTENANCE

Hydraulic Steering Maintenance can be covered in three categories that generally will include any complaint on the operation of the unit. These three categories, leaks, noise and hard steering, if properly handled will correct the majority of complaints that may be encountered regarding the unit's operations.

Care, Maintenance and Adjustments

Cleanliness is a highly important factor in the service of the power steering unit. If dirt enters the hydraulic system it will cause noise, leaks or improper operation. When working on a power steering unit be sure to completely clean the outside before disassembly. Be sure the bench is free of dirt, then lay the parts on clean paper. Careful thought to cleanliness while disassembling and reassembling the power unit will prevent having dissatisfied owners and a job that must be done over.

LEAKS

If the complaint is oil loss in the power steering unit, the following steps should be performed. First, wipe the complete unit dry. This includes the pump, hoses, power cylinder, and control valve. Then fill the reservoir, start the engine, operate the steering unit and observe where the leak occurs. The position of the leak will then give an indication of the cause.

A possible place for leakage would be at the pump, involving either the reservoir to pump body seal or the pump drive shaft oil seal. In the case of pump leakage the repair is fairly simple requiring very little time to replace the seals. Other leaks may require removal of the unit from the car and more involved service. Improperly installed seals is a major cause of leaks. Damage to "O" ring seals will cause leaks if the housings have sharp edges which cut the "O" rings. Sharp edges should be removed with a fine stone and new seals installed.

NOISE

When the complaint is excessive noise it is sometimes hard to isolate the sound. Following is a quick check to determine whether or not the steering unit is at fault. Disconnect the pump drive belt and operate the car. If the noise is no longer present then make the power steering unit the next check.

CAUTION: Do not operate the engine too long with the belt disconnected since the water pump is also driven by this belt and the engine may become overheated.

Another good thing to remember is never diagnose a power steering complaint without first checking fluid level and drive belt tension. Either may cause noises and malfunctions which could conceivably be blamed on the steering unit. When checking fluid level, be sure bubbles are not present in the fluid. If bubbles are found, the bleeding procedure outlined under "Bleeding Hydraulic System" should be performed.

Another cause of noise in the pump can be a sticky valve which will produce a buzzing sound. This can be determined by checking for excessive pump pressure with oil pressure gauge, Tool J-5176, outlined under "Checking Pump Pressure."

Obstructions in the hydraulic system will also cause a noise. For instance, a slight burr on the edge of one of the valve spool lands or a hose restriction will cause a noise on turns. Removal of the burr with a fine stone or replacement of the hose will be necessary for correction.

If belt noise, possibly accompanied by a knock or steering wheel oscillation, is present on extreme turns, it's reasonable that improper pump belt tension is the cause.

HARD STEERING

Dirt in the system has been found to be a cause of hard steering as greater effort is required to reposition the spool and bring the power steering into operation. The repair will be a complete cleaning of the hydraulic system. A pump relief valve stuck in the open position can be the cause of hard steering as there will be zero pump pressure. This can easily be checked by using oil pressure gauge J-5176.

Fluid Level

Check oil level in the reservoir by removing the reservoir dip stick to determine oil level as indicated by fluid showing on the dip stick (fig. 44).
Fill to level with automatic transmission fluid "Type A" bearing an "AQ-ATF" number. This is the same oil as available for Powerglide transmissions and is available through Chevrolet Dealer and Oil Company filling stations. Total in system is 1 1/2 pts.

BLEEDING HYDRAULIC SYSTEM

After a pump or control valve has been installed or a disconnected oil line is reconnected, the air that entered the hydraulic system must be bled out, otherwise noisy and unsatisfactory operation will result. The following procedure should be used to bleed the hydraulic circuit:

Fill oil reservoir to proper level and let oil remain undisturbed for about two minutes.
Raise front end of vehicle so that wheels are off the ground.
Start the engine and run at idle for two minutes.
Increase engine speed to approximately 1500 RPM.
Turn the wheels (off ground) right and left, lightly contacting the stops.
Lower the car and turn the wheels right and left on the ground.
Recheck for leaks.
Check oil level and refill as required.

PUMP BELT TENSION

Adjustment

Loosen the outer bracket to generator bolt and retaining bolt on the generator rear brace (fig. 43).
Pull the generator out from the engine with all slack taken out of the belt.
Tighten the retaining bolts.
Push in on the belt midway between the water pump and generator pulleys with light push.
If tension is correct there will be 5/16 inches of deflection on 6 cylinder and 13/16 inches on 8 cylinder with a light push at this point.

CHECKING PUMP PRESSURE

Disconnect the pressure line at the pump connection (smallest, top line). CAUTION: Some fluid will leak out when the line is disconnected so provision must be made to collect this drainage.
Install checking gauge tool J-5176 (with gauge valve closed) on the pump and hose connection. NOTE: Adapter kit J-5900 must be used to adopt pressure gauge to pump.
Open the gauge valve and run engine at idle.
Turn wheels (on ground) against stops. Pressure should not be less than 750 psi.
If pressure is less than 750 psi, slowly close gauge valve observing gauge for pressure increase. Pressure will increase as valve is closed if pump is good. CAUTION: Do not leave valve closed for more than 15 seconds.
If pressure does not increase when the valve is closed, difficulty is in the pump, which must be removed for service.
Shut engine off, remove gauge and valve, reconnect hose to pump if pressure is O.K.
Bleed hydraulic system of air as outlined under "Bleeding Hydraulic System."

STEERING WHEEL ALIGNMENT

Refer to Section 9. Steering Wheel Alignment.

Major Service Operations

RESERVOIR AND PUMP ASSEMBLY

Removal NOTE: Omit steps 1 and 2 on 8 cylinder models.

Loosen generator to bracket retaining bolts and remove fan belt.
Pull the generator all the way out from the engine.
Place a container under the pump and disconnect the hydraulic lines from the pump allowing the oil to drain out of the reservoir into the container (fig. 45).
Remove the retaining bolts from the pump to generator and generator rear brace on 8 cylinder models and remove the pump from the vehicle (fig. 46).
Complete draining the remaining oil from the pump reservoir before disassembly.

Disassembly

Remove the two retaining bolts and sealing washers from pump reservoir to pump cover assembly (fig. 47).
Remove the reservoir from the pump assembly.
Remove the oil filter spring retainer from the pump cover assembly.
Remove the spring retainer and plate from the pump cover assembly.
Remove plug and "O" ring, flow spring and pressure relief valve assembly from the pump cover assembly.
Remove the three retaining bolts from the pump cover assembly.
Remove the pump cover from the pump body assembly and remove the oil filter and retainer.
Remove the cam ring, pump rotor and vanes.
Remove the pressure plate from the pump cover assembly.
Remove and discard the "O" rings from the pump cover, cam ring, and pump body.
Remove and discard the generator shaft oil seal from the pump body assembly.

Cleaning and Inspection

Wash all parts in cleaning solvent and wipe dry with a lint free cloth.
Inspect the fit of vanes in rotor. Vanes must slide freely, but snugly in slots. Tightness may be relieved by thorough cleaning or removal of irregularities.
Inspect flat faces of pressure plate, cam ring, pump cover, rotor and pump body. These faces may be repaired by lapping until smooth and flat, after which all lapping compound must be thoroughly washed away.
Inspect cylindrical surface of pressure relief control valve and check fit of pressure relief control valve in pump cover. Slight irregularities may be corrected by polishing.

Assembly

Lubriplate and install new "O" rings in the pump cover, on the cam ring, and in the pump body.
Install the rotor and vanes on the pump body with wear pattern or beveled edge of vanes against cam ring inner diameter.
Install the alignment sleeve in the cam ring and install the cam ring on the pump body. CAUTION: The wider edge of the cam ring is the correct side to the pump body. Be certain to align bolt holes in the cam ring to pump body bolt holes. The rotor should be installed with the rounded side of the splines toward the generator end of the pump.
Install the pressure plate in the pump cover.
Install the filter retainer and oil filter on the pump cover.
Install the pump cover assembly and three retaining bolts to the pump body.
Install the plunger and flow spring in the pump cover assembly.
Install the plug and "O" ring assembly, cover plate, and retainer spring.
Install the oil filter retainer spring in the pump cover.
Install the reservoir, two retaining bolts, and two sealing washers. NOTE: The brass fitting seats are of the pressed in type and are replaceable in the event of a fitting leak by tapping threads in the hole of the seat and then pulling the seat by using a bolt threaded into the tapped out seat and a flat washer and nut as an extractor.
When installing new seats, align the seat in its bore and press it into place using the correct hose or tube fitting as a pressing tool.
Install pump on vehicle and fill and bleed system as outlined under "Care, Maintenance and Adjustments."

Control Valve

Removal

Raise the front of the vehicle off the floor and place it on stands.
Loosen the relay rod to control valve clamp (fig. 48).
Disconnect the two pump to control valve hose connections and allow fluid to drain into a container, then disconnect the two remaining valve to power cylinder hoses.
Remove the retaining nut from the ball stud to pitman arm connection and disconnect the control valve from the pitman arm.
Turn the pitman arm to the right clear of the control valve and unscrew the control valve from the relay rod (fig. 49).
Remove the control valve from the vehicle.

Disassembly

Remove dust shield (1) (fig. 50) from the control valve housing (2).
Remove retaining pin and nut (3) from the valve shaft.
Remove the retaining bolts connecting the valve assembly housing to the adapter assembly housing and separate the two assemblies. NOTE: Valve spool remains in the housing when the two assemblies are separated, because the seal at the end of the spool will not allow spool removal other than from the end of the housing.
Remove the spring thrust washer (7), spring (8), flat washer (9), vee seal assembly small washer and spacer (15) from the valve shaft.
Remove the ball stud cover (13) (fig. 41) from the adapter assembly housing (11).
Push the ball stud (8) to the end of the adapter housing and remove the lock pin (4).
Remove the threaded ball plug adjuster (3) and valve shaft (1).
Remove the ball seat plug (5) and spring (6).
Remove the ball seats and ball stud.
Remove the bearing sleeve (10).

Inspection

Wash all metal parts in solvent cleaner and dry them with a lint free cloth.
Inspect all parts for scratches, burrs, distortion, evidence of wear and replace all worn or damaged parts, including mating parts where necessary.
Replace all seals, gaskets, covers with approved service parts.

Assembly

Replace the ball seat (9) (fig. 41) in the bearsleeve (10) and insert the sleeve in the housing (11).
Insert the ball stud (8) in the sleeve.
Install the remaining ball seat (7), spring (6) and spring seat (5j in the bearing sleeve. CAUTION: This is the heavier of the two springs used in the control valve.
Install the valve shaft (1) in the adjuster (3) and screw the adjuster into the bearing sleeve. NOTE: The adjuster should be tightened until bottoms, and should then be backed off 1/4 turn plus or minus amount necessary to insert lock pin in nearest hole. CAUTION: Be sure ball seats remain in correct position, otherwise there will be insufficient clearance to correctly install the retaining pin.
Install the ball stud cover (13).
Install the washer (2) fig. 41 and annulus spacer (15) fig. 50 on the valve shaft.
Install the vee seal block (14) fig. 50 and ring assembly (10, 11, 12, 13) fig. 50.
Install the annulus washer, spring and spring thrust washer (7) fig. 50. CAUTION: Chamfer side of the thrust washer to be toward spool side.
Install the spool valve assembly and retaining nut. CAUTION: The spool valve is installed with the vee seal at the threaded end of the valve shaft.
Tighten the retaining nut to 25 in. lbs. with a torque wrench and install the retaining clip. CAUTION: Be sure all parts including spring, are correctly located before tightening.
Insert the assembled valve and adapter assembly into the valve housing and install the two retaining bolts and lockwashers.
Fill the end area with GM 4617-M grease and install the valve housing dust cover.

Installation

Install the control valve on the relay rod (fig. 51) so that the distance from center of control valve ball stud to the center of the tie rod end ball stud measures approximately 3 5/8".
Tighten the control valve clamp. NOTE: The clamp securing the control valve to the relay rod end should be positioned before tightening so that it will not interfere with the steering linkage.
Reconnect the four hydraulic hoses to the control valve.
Fill the system with type "A" fluid and bleed out air using the procedure outlined under "Care, Maintenance and Adjustments."

Power Cylinder

Removal

Disconnect the two hydraulic lines (5) (fig. 52) connected to the power cylinder and drain fluid into a container.
Remove retaining nut, washer, and rubber grommet from power cylinder rod to the brace attached to the frame.
Remove the cotter pin, retaining nut, flat washer and bolt from the end of the power cylinder where it is fastened to the relay rod bracket.
Remove the power cylinder from the vehicle.

Inspection

Inspect the seals for leaks around the cylinder rod and if leaks are present replace the seals, using the following procedure:
- Use a hook tool and remove the retaining ring (fig. 53).
- Remove the wiper ring.
- Remove the back up washer.
- Remove the back up ring seal.
- Remove the seal. NOTE: The piston rod seal should not be removed unless there are signs of leakage along the piston shaft at the shaft seal.
Examine the brass fitted hose connection seats for cracks or damage and replace if necessary.
For service other than seat or seal replacement, replace the power cylinder.

Installation

Install the power cylinder on the vehicle by reversing the removal procedure.
Reconnect the two hydraulic lines, fill the system with fluid and bleed out air using the procedure outlined under "Care, Maintenance and Adjustments."

Trouble Diagnosis

This section will cover only those causes of trouble which may be due to the hydraulic power steering mechanism. Before assuming that the hydraulic power mechanism is at fault, make sure the mechanical components are in good condition. The mechanical items include: front wheel alignment, tire condition and pressure, wheel bearing adjustment, lubrication and adjustment of steering linkage, and proper alignment of steering gear in mounting to eliminate bindings.

1. HARD STEERING

To determine whether hard steering actually exists, place car on a clean, dry floor, apply brakes, and with engine idling, turn wheel to the extreme right and left and hold against the stop momentarily in each direction several times. This will bring the oil temperature to approximately 170°F which is operating temperature. Apply Steering Wheel Checking Scale, J-5178 (15 lbs.) to a spoke at rim of steering wheel and check the pull required to turn the wheel steadily with gauge held at 90 degrees to the spoke. If the pull required to turn the wheel exceeds 10 pounds, check the following causes.

Possible Causes

Generator drive belt loose.
Low oil level in reservoir.
Air in hydraulic system.
Insufficient oil pressure.
Steering adjustment tight.

2. EXCESSIVE PLAY OR LOOSENESS IN STEERING MECHANISM

Possible Causes

Loose worm thrust bearing adjustment.

3. LOW OIL PRESSURE

If it is believed oil pressure is low, the pressure should be checked as outlined in "Care, Maintenance and Adjustments" using pressure gauge, J-5176.

Possible Causes

Generator drive belt loose.
Low oil level in reservoir.
Pump mechanical difficulty-possibly caused by:
1. Relief valve; improper adjustment, weak relief valve spring or relief valve stuck open.
2. Control valve stuck or broken flow control spring.
3. Worn rotor parts.
Pressure loss in steering control valve, possibly caused by sticking valve spool or discharge valve stuck open.
Pressure loss in power cylinder, possibly caused by leaking seal.
External or internal oil leaks.

4. POOR CENTERING OR RECOVERY ON TURNS

Possible Causes

Valve spool sticking in valve housing.
Binding of steering shaft.
Loose worm thrust bearing adjustment.
Sticky cylinder assembly.

5 OIL PUMP NOISY

Possible causes

Improper oil level.
Air in system.
Reservoir air vent plugged.
Sludge or dirt in pump.
Pump bearings, shaft, vanes or other rotating parts worn or damaged. Sticking pump vanes also a possibility.

6. OIL LEAKS

External-Possible Causes

Loose connections at hose unions or oil pipe elbows.
Loose connection or faulty "O" rings in pump.
Hose leaks.

Internal-Possible Causes

Leaking housing.
Cylinder seal leaking.

Assembly Manual

Steering Mechanism
Steering Linkage
Steering Gear
Steering Wheel
Steering Gear Clamp
Steering Column and Clutch Rod Dash Seal
Hydraulic Steering
Hose Shield
Power Steering Bleeding
Generator
Hose
Linkage Mechanism