Steering Gear - Power Ford Bronco II I

DESCRIPTION

Integral power steering unit consists of a worm and one-piece rack/piston, meshed to sector shaft teeth. Hydraulic control valve, input shaft, and torsion bar assemblies mount to end of worm shaft and are operated by twisting action of torsion bar. One-piece rack/piston, worm and sector shaft are mounted in one housing. Valve spool is mounted in an attached housing.

TROUBLE SHOOTING

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

LUBRICATION & TESTING

See POWER STEERING GENERAL SERVICING article in this section.

OVER-CENTER POSITION

1. Using Pitman Arm Puller (T64P-3590-F), disconnect pitman arm from sector shaft. Disconnect fluid return line at pump reservoir. Cap reservoir return line pipe. Place end of return line in clean container.
2. Turn steering wheel in both directions several times to drain fluid. Remove horn button from steering wheel. Turn steering wheel until positioned 45 degrees from left steering stop.
3. Using an INCH lb. torque wrench on steering wheel nut, measure force required to turn steering shaft 1/8 turn from 45 degree position. Turn steering wheel back to center position. Measure force required to move steering shaft back and forth across center position.
4. Loosen lock nut. Turn adjusting screw until reading across center position is 14-18 INCH lbs. (1.6-2.0 N.m) greater than reading across 45 degree position. Tighten lock nut while holding adjusting screw in place. Attach pitman arm. Reconnect hoses. Attach horn button.

Scheme 4

VALVE SPOOL CENTERING

1. Install a 0-2000 psi pressure gauge and valve assembly between power steering pump and high pressure line. Open gauge valve completely. Remove horn button from steering wheel.
2. Attach an INCH lb. torque wrench to steering wheel nut. Power steering fluid must be at normal operating temperature and at correct level. Steering wheel must be centered.
3. Set engine idle to 1000 RPM. Using torque wrench, rotate steering shaft to either side of center to obtain reading of 250 psi (17.5 kg/cm 2 ) in each direction.
4. Torque reading should be equal in both directions when 250 psi (17.5 kg/cm 2 ) is reached. If difference between readings exceeds 6 INCH lbs. (.68 N.m), replace shaft and control assembly.

Note. When performing test off vehicle, take torque and pressure readings at right and left stops instead of either side of center.

Removal

1. Disconnect hydraulic lines at power steering gear. Cap lines and ports to prevent contamination. Remove splash shield from flex coupling. Disconnect flex coupling at steering gear. Raise and support vehicle.
2. Remove pitman arm nut and washer. Using Pitman Arm Puller (T64P-3590-F), remove pitman arm from sector shaft. Take care not to damage seals.
3. Support steering gear. Remove steering gear attaching bolts. Work steering gear free of flex coupling. Remove steering gear from vehicle.

Installation

1. Slide flex coupling into position on steering shaft assembly. Turn steering wheel so spokes are in horizontal position. Center steering gear input shaft with indexing flat facing down.
2. Install input shaft into flex coupling. Position gear on frame. Install and tighten bolts. With wheels in straight-ahead position, install pitman arm on sector shaft. Install and tighten washer and nut on pitman arm.
3. Install splash shield. Connect and tighten hydraulic lines to gear. Disconnect coil wire. Fill reservoir to proper level. Turn ignition on and turn steering wheel left to right to distribute fluid. Add fluid (if necessary).

OVERHAUL

Note. If complete gear assembly is not to be overhauled, remove specific unit. Proceed to disassembly and reassembly of that unit.

Disassembly

1. Drain steering gear completely. Mount gear in a soft-jawed vise. Remove lock nut and washer from adjusting screw. Turn input shaft from lock to lock, noting number of turns. Turn shaft back 1/2 that number to center gear.
2. Remove sector shaft cover attaching bolts. Tap lower end of sector shaft with a soft faced hammer to loosen shaft in bore. Lift shaft and cover assembly from housing. Discard cover "O" ring.
3. Turn sector shaft cover counterclockwise to remove it from adjusting screw. Remove valve housing attaching bolts and identification tag. Lift valve housing from steering gear housing while holding piston to prevent it from rotating off worm shaft.
4. Remove valve housing and gasket. Discard gasket. With piston held so that ball guide faces up, remove ball guide clamp screws and ball guide clamp.
5. Over a clean container, placing finger over opening in ball guide, turn piston so ball guide faces down. Let guide tubes fall into container.
6. Rotate input shaft lock to lock until all balls fall from piston into container. Remove valve assembly from piston. Ensure that all balls have been removed.
7. Install valve body assembly in bench mounted Holding Fixture (T57L-500-B) or vise. Loosen hex head race nut screw from bearing race nut. (Scheme 5) Carefully slide input shaft, worm and valve assembly out of valve housing.

Scheme 5

Scheme 6

1. Mount valve housing in holding fixture with flanged end up. Lightly lubricate Teflon rings on valve sleeve. Carefully install worm and valve in housing.
2. Install race nut in housing. Tighten nut securely. Install Allen head race nut set screw through housing. Tighten set screw. Place piston on bench with ball guide holes facing up.
3. Insert worm shaft into piston so that first groove is in line with hole nearest center of piston. Place ball guide in piston. Place a minimum of 27 ball bearings in ball guide while turning worm counterclockwise as viewed from input end of shaft.
4. If all balls have not been fed into guide upon reaching left stop, rotate input shaft in one direction and then other while inserting remaining balls. DO NOT rotate input shaft more than 3 turns from left stop or balls will fall out of circuit.
5. Secure guides in ball nut with guide clamp. Apply petroleum jelly to Teflon seal on piston. Place a new "O" ring on valve housing. Taking care not to damage piston ring, slide piston and valve into gear housing.
6. Align oil passage in valve housing with passage in gear housing. Place new "O" ring in oil passage hole of gear housing. Install identification tag on housing on upper right valve housing bolt.
7. Loosely install housing attaching bolts. Rotate ball nut so that teeth are in same place as sector teeth. Tighten valve housing bolts. Place sector shaft cover "O" ring in gear housing. Turn input shaft to center piston.
8. Apply petroleum jelly to sector shaft journal. Place sector shaft and cover into gear housing. Install and tighten cover bolts. Perform over-center adjustment. See «OVER-CENTER POSITION»(/ford/bronco-ii/i-1984-1990/remont/manual-power-steering/#steering-gear-power__over-center-position) .

Scheme 7

1. Remove snap ring from lower end of gear housing. Using Puller Attachment and Slide Hammer (T58L-101-A and T59L-100-B), remove dust seal and pressure seal from housing.
2. Lubricate sector shaft seals and bore with Lubriplate. Place dust seal on Seal Installer (T77L-3576-A) so raised lip of seal faces installer. Place pressure seal on installer so lip faces away from installer. (Scheme 7)
3. Flat back side of pressure seal should be against flat side of dust seal. Insert installer into sector shaft bore. Drive in until seals clear snap ring groove. Do not bottom seals against bearing. Install snap ring.

Scheme 8

1. Using Puller Attachment and Slide Hammer (T58L-101-A and T59L-100-B), remove dust seal from rear of valve housing. Discard seal. Remove snap ring from valve housing.
2. Invert valve housing. Using Input Shaft Bearing and Seal Remover (T65P-3524-A2 and T65-3524-A3) in valve body assembly opposite oil seal end, tap bearing and seal out of housing.
3. Using Tube Seat Remover (T74P-3504-L), remove inlet and outlet tube seats (if damaged).

Reassembly

1. Coat new tube seats with petroleum jelly. Install them in housing. Install bearing with metal side covering rollers facing outward. Press bearing into housing.
2. Dip new oil seal in power steering fluid. Place seal in housing with metal side out. Drive seal into housing until outer edge does not quite clear snap ring groove.
3. Install snap ring in housing. Place dust seal in housing with dished rubber side out. Drive into place until seal is located behind undercut in input shaft.

Scheme 9

Disassembly & Reassembly

1. Using a small knife, remove rings from sleeve. Take care not to scratch sleeve. Mount worm end of worm/valve sleeve assembly in soft-jawed vise. Place Mandrell (T75L-3517-A1) on sleeve. Using Driver (T75L-3517-A2), install rings one at a time.
2. Rapidly push down on driver to force ring down ramp and into fourth groove of valve sleeve. Repeat 3 more times, adding Spacers (T75L-3517-A3), one additionally for each ring, under mandrell to line up next groove.
3. After all sleeve rings are installed, place Sizer (T75L-3517-A4) carefully over valve sleeve rings. Ensure rings are not bent over when tube is installed. Remove sizer. Check that rings turn freely.

Remove teflon ring and "O" ring from piston and ball nut assembly. Dip new "O" ring in power steering fluid. Place it on piston and ball nut. Install new Teflon ring on piston and ball nut, using care not to over-stretch ring.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES
• POWER STEERING GENERAL SERVICING
• OVER-CENTER POSITION