Steering Gear - Power Chevrolet Camaro II

DESCRIPTION

Gear is variable ratio recirculating ball bearing type. Steel ball bearings work as a rolling thread between steering gear worm shaft and rack-piston nut. Worm shaft is supported by a thrust preload bearing and 2 conical thrust races at lower end, and a bearing assembly in adjuster plug at upper end. This design provides continual spring loaded pressure on worm shaft to prevent loss of thrust bearing preload for life of gear.

Adjuster plug provides initial preload adjustment and service adjustment when servicing gear. As worm shaft is turned right, rack-piston moves upward in gear; turning worm shaft left moves rack-piston downward in gear. Rack-piston teeth mesh with sector which is forged as part of pitman shaft. Turning worm shaft turns pitman shaft which turns wheels through mechanical linkage.

Note. Model 605 (Small Gear) is similar to the model 800-808 (Large Gear) described above with the following exceptions

1. Small gear has a round side cover held in place by a retaining ring while large gear has a rectangular side cover held in place with 4 bolts.
2. The worm and rack are directly mated rather than separated by recirculating ball bearings as in the large gear.
3. Thrust bearing adjustment is at lower end of gear by hex -driver instead of at stub shaft end with spanner.

TROUBLE SHOOTING

Refer to TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

LUBRICATION & TESTING

For further information see POWER STEERING GENERAL SERVICING article in the STEERING section.

ADJUSTMENT

Note. If complete wheel alignment is necessary, refer to the appropriate WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article listed below in the WHEEL ALIGNMENT section

1. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54259) for 98, Bonneville, Caballero, Cutlass (RWD), DeVille, El Camino, Grand Prix, Malibu, Monte Carlo, Regal.
2. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54260) for 88, Caprice, Custom Cruiser, Impala, Parisienne.
3. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54261) for Eldorado, Riviera, Toronado.
4. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/chevrolet/camaro/ii-1970-1987/remont/wheel-alignment/#wheel-alignment-specifications-procedures) for Camaro, Firebird.
5. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54263) for Skylark.
6. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54264) for Electra/Park Avenue.
7. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54265) for Fleetwood (RWD)
8. «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(ref-54266) for Seville.

Note. Due to difficulty in adjusting worm bearing preload and drag induced by hydraulic oil, adjustments should be made with gear removed from vehicle. Thrust bearing adjustment procedures follow. Some service gears and overhaul kits may have flat races. If uncertain about race type, perform thrust bearing preload for conical thrust races to determine type used.

Saginaw Rotary Valve Power Steering Gear (800-808 Shown) Model 605 (Small Gear) is similar. Scheme 1

Thrust Bearing Preload

1. Drain gear fluid by rotating stub shaft from lock-to-lock several times. Mount gear in vise and remove adjuster plug lock nut.
2. Using spanner wrench for large gear or hex driver for small gear, turn adjuster plug until plug and thrust bearings are firmly bottomed (about 20 ft. lbs. (27 N.m) for large gear or 30 ft. lbs. (41 N.m) for small gear).
3. Scribe an index mark on housing and adjuster plug. Measure 1/2" counterclockwise and mark housing.
4. Back up adjuster plug so mark aligns with new mark on housing and tighten lock nut while holding adjuster plug to maintain position. Check for 4-10 INCH Lbs. (0.4-1.1 N.m) torque required to turn stub shaft. (Scheme 2)

Model 800-808 (Large Gear) Thrust Bearing Preload Adjustment Model 605 (Small Gear) is similar. Scheme 2

Pitman Shaft Overcenter Sector Adjustment

1. Ensure that gear is at center of travel. Back off preload adjuster until it stops. Turn in 1 full turn. (Note that small gear has LEFT HAND THREADS on adjuster and lock nut.)
2. Check torque required to turn stub shaft and turn adjuster in until 6-10 INCH Lbs. (0.7-1.1 N.m) more torque is required to turn shaft. Tighten adjuster screw lock nut and recheck torque. Total torque required should not exceed 14 INCH Lbs. (1.5 N.m) for used gear or 18 INCH Lbs. (2.0 N.m) for new gear. (Scheme 3)

Pitman Shaft End Play Adjustment. Scheme 3

Removal & Installation

1. Place drain pan under gear to catch fluid. Remove pressure and return lines. Plug openings to prevent contamination and loss of fluid. Disconnect battery negative cable.
2. Remove stone shield from flexible coupling. Remove pinch bolt and disconnect flexible coupling from worm shaft. Remove pitman arm nut and scribe an alignment mark on pitman arm and shaft for reassembly reference.
3. Using a puller, remove pitman arm. Remove gear attaching bolts and lower gear from vehicle. To install, reverse removal procedure, ensuring that hoses do not rub against chassis.

Note. If complete assembly is not to be overhauled, remove unit to be serviced and proceed to disassembly and reassembly of that unit.

Disassembly

1. Thoroughly clean exterior and drain as much fluid as possible from steering gear. Use soft jaws on vise to hold unit. Remove pitman shaft preload adjuster nut. Rotate stub shaft to center gear.
2. On small gear, use punch through retaining ring guide hole to lift retaining ring and remove side cover retaining ring. On large gear, remove side cover retaining bolts.
3. Tap on pitman shaft end with soft faced hammer to remove pitman shaft and cover. On small gear, loosen adjuster lock nut and back out adjuster plug. Push on stub shaft and remove rack piston and valve assembly together.
4. On large gear, use punch through retaining ring access hole to lift ring and pry retaining ring from gear. Rotate stub shaft counterclockwise only enough to push out end cover.
5. Remove rack piston plug and insert ball bearing retainer (J-21552). Hold retainer and turn stub shaft counterclockwise to force rack piston onto tool.
6. Remove lock nut and adjuster plug assembly from stub shaft end. Grasp stub shaft end and pull valve and worm assembly from housing bore. Separate valve from worm, noting that pin in worm fits slot in valve.
7. On small gear, turn valve and worm assembly counterclockwise to separate from rack. Remove retaining ring holding worm to valve and separate worm and valve assembly.

Reassembly

1. Lubricate all parts with power steering fluid. Install all parts in reverse order of removal. (Scheme 1) Install lower shaft cap "O" ring in valve body so it is seated against lower shaft cap.
2. Align narrow notch in valve body with pin in worm. Install valve shaft assembly in gear housing. Valve body is properly seated when oil return hole in housing is entirely uncovered.
3. Install new "O" ring in adjuster plug groove. Place seal protector (J-6222) over stub shaft. Install adjuster plug assembly in housing until it seats against valve body. Remove seal protector.
4. Position seal compressor against shoulder of housing. With ball bearing retainer (J-21552) in place in rack piston. Push rack piston into housing until tool contacts center of worm.
5. Turn lower shaft clockwise to thread rack piston onto worm shaft, remove tool. Install new "O" ring in pitman shaft side cover. Turn lower shaft until rack piston teeth are centered in pitman shaft opening.
6. Install shaft and cover so center tooth of pitman shaft engages center groove of rack piston. Install side cover bolts and tighten.
7. Install rack piston plug and tighten. Install housing end plug "O" ring, fill gear end with power steering fluid. Install end plug and retaining ring. Perform steering gear adjustments before installing gear in vehicle.

1. Remove thrust bearing retainer being careful not to score needle bearing bore. Remove thrust bearing spacer, bearing and bearing races. Remove adjuster plug "O" ring and stub shaft seal snap ring.
2. Remove dust seal. Remove stub shaft seal. Inspect adjuster plug needle bearings for being broken or pitted. Remove bearing by pressing from thrust bearing end.

Inspection

Inspect thrust bearing spacer for cracks and bearing rollers for pitting or scoring. Check bearing races for scoring, cracks or brinelling. If any of these conditions exists, replace both thrust bearing races and spacer.

Removing Upper Thrust Bearing Retainer Large gear shown, small gear similar. Scheme 4

Adjuster Plug Assembly. Scheme 5

1. Press needle bearing into adjuster plug with identification marks facing press tool until bottomed on input shaft seal bore. Install input seal with spring in seal facing inside of adjuster plug.
2. Install adjuster plug "O" ring. Assemble thrust bearing, thrust bearing races, and thrust bearing spacer on adjuster plug. Using a brass or wooden dowel, press bearing retainer into needle bearing bore.

ROTARY VALVE

Note. Complete valve assembly is hydraulically balanced during manufacture. If replacement of any part other than rings or seals is necessary, replace complete valve assembly.

1. Remove and discard "O" ring seal in shaft cap end of valve assembly. While holding assembly with lower shaft down, lightly tap stub shaft against bench until shaft cap is free in valve body.
2. Pull shaft assembly until shaft clears body by approximately 1/4". DO NOT pull shaft assembly too far or spool valve may become cocked in valve body. Disengage shaft pin from valve spool and remove shaft assembly. Push spool valve out flush end of valve body until dampener "O" ring is exposed.
3. Pull spool from body while rotating valve. If spool becomes cocked, realign valve, then remove. Remove dampener "O" ring from spool valve and discard. Cut plastic oil rings and "O" rings from valve body and discard.

1. Check spool valve drive pin for cracks or excessive wear. Replace complete valve shaft assembly as required. Check machined surfaces of stub shaft and spool valve for nicks, scratches or bad wear spots.
2. If nicks cannot be cleaned up with crocus cloth, replace complete valve and shaft assembly. A slight polishing is normal on valve surfaces. If small notch in valve skirt is worn, replace valve assembly.
3. Lubricate spool valve and check fit in valve body with "O" ring removed. If binding occurs, replace valve and shaft assembly. Small flat spots on either side of spool valve drive pin head are normal.

Rotary Valve & Stub Shaft Assembly. Scheme 6

Removing Stub Shaft Assembly. Scheme 7

Stub Shaft Installation. Scheme 8

1. Lubricate back-up "O" ring seals and install on valve body. Avoid twisting seals. Install valve plastic rings over "O" rings. Lubricate new spool valve damper "O" ring with petroleum jelly and install in spool groove.
2. Lubricate spool valve and slide into valve body until shaft pin hole is visible from other end (spool valve flush with cap end of valve body). Carefully install shaft assembly into spool valve until shaft pin can be inserted into spool valve.
3. Align notch in shaft cap with pin in valve body and press spool valve and shaft assembly into valve body. Lubricate new cap-to-worm shaft "O" ring and install in valve body. Check that shaft cap notch is mated with valve body pin before installing valve body into gear assembly.

Remove pitman shaft adjuster lock nut and unscrew side cover from adjusting screw. (LEFT HAND THREAD on small gear.) DO NOT disassemble pitman shaft.

1. Clean and dry all parts. If shaft bearing surface in side cover is badly worn or scored, replace side cover. Make sure sealing and bearing surfaces of pitman shaft are not rough, cracked, nicked, or badly scored.
2. If shaft teeth are damaged, replace shaft. Check pitman shaft free play adjusting screw for ease in turning with no end play. If adjusting screw is loose, replace pitman shaft assembly.

Thread side cover onto pitman shaft adjusting screw until it bottoms, turn in 1/2 turn. Install new adjusting screw lock nut and make over-center adjustment. See Steering Gear Adjustment.

RACK PISTON & WORM

Note. Procedures for small gear are similar except for reference to recirculating ball bearings which are used only with large gear.

Remove piston ring and back-up "O" ring from rack-piston nut. Remove ball bearing return guide clamp, ball bearing return guide, arbor tool and all ball bearings from rack-piston.

Clean and dry all parts. Inspect worm and rack-piston grooves for scoring. Inspect ball bearings for damage. Check ball bearing guides for pinching at ends. Inspect lower thrust bearing races for cracks, scoring or pitting.

Note. If either worm or rack-piston is damaged, both must be replaced as a matched set. If any ball bearings are damaged, replace entire set.

Worm and Valve Body Assembly Large gear shown small gear is similar. Scheme 9

1. Install "O" ring on rack-piston, using care not to twist rings. Install worm into rack-piston until worm is against piston shoulder. Install light and dark colored ball bearings alternately into rack piston while turning shaft slowly counterclockwise.
2. Pack one ball bearing return guide half with petroleum jelly and place remaining ball bearings in guide. Ball bearings in guide must alternate color in same sequence as ball bearings in rack piston.
3. Install guide clamp and tighten clamp attaching screws. Install ball bearing retainer tool (J-21552) and withdraw worm shaft from rack-piston. Leave tool in place and install rack-piston in housing.

PITMAN SHAFT SEALS & BEARING REPLACEMENT

Note. Seals may be replaced with steering gear on or off vehicle.

Removal

Remove seal retaining ring, washers and inner seal. Remove needle bearing from pitman arm end of housing with a bearing driver.

Installation

1. Press bearing into housing until flush with shoulder. Coat seal lips and washers with anhydrous calcium grease. Using a seal driver, install seals with lips facing inward.
2. Press seals in only far enough to allow clearance for washers and retaining ring. DO NOT drive bearing or seals into housing farther than is necessary. Press bearing on stamped end only. Install retaining ring. Be sure ring is completely seated in housing groove.

STEERING GEAR HOSE CONNECTOR SEATS & CHECK VALVE

1. Turn gear up side down or pack inside of connector seats with petroleum jelly to prevent chips from entering housing.
2. Use a screwdriver or a No. 4 screw extractor to remove connector seats. Wipe housing clean and remove check valve and spring from pressure port on large gear.

1. Install new check valve spring with large end down. Make sure spring is seated in counterbore. Install new valve over spring with tangs pointing down.
2. Install connector seat using petroleum jelly to hold seat on valve, and drive seat into place using installer tool (J-6217).

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• POWER STEERING GENERAL SERVICING
• WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES