JEEP CHEROKEE 1988 Service Repair Manual

Fig. 4: Power Steering Pump (Cherokee & Commanche)

Fig. 5: Front Bracket Boltsp (Cherokee & Commanche)
STEERING GEAR
Removal
1) Remove collapsible steering column. Raise and support
vehicle. Place drain pan under steering gear assembly. Center steering
gear. Disconnect hydraulic hoses from gear and cap ends. Disconnect
steering linkage from pitman arm. Remove pitman arm from gear.
2) Remove flexible coupling clamp bolt and bolts retaining
steering gear to frame. Disconnect gear from flexible coupling and
remove gear from vehicle. On Jeep CJ7 and Scrambler models, remove
steering gear and mounting bracket as an assembly.
Installation
To install, reverse removal procedure. Fill pump reservoir.
Bleed air from system. See POWER STEERING GENERAL SERVICING article.

OVERHAUL
SUBMERGED VANE POWER STEERING PUMP
Disassembly
1) Drain pump reservoir. Clean exterior of unit. Measure
distance shaft protrudes from pulley, and record for assembly
reference. Using pulley remover, remove pulley from shaft. Clamp pump
in vise; DO NOT overtighten vise. Remove pressure line union,
reservoir mounting stud and reservoir. See Fig. 6. Remove and discard
pressure line union "O" rings.
Fig. 6: Exploded View of Pump Assembly (Grand Wagoneer & Wrangler)
Courtesy of Chrysler Motors
2) Using punch and screwdriver, remove end plate retaining
ring. Remove end plate and pressure plate spring. Remove "O" ring,
flow control valve and spring. Note direction of pump ring
installation for reassembly reference.
3) Using soft-faced hammer, tap end of drive shaft to loosen
pressure plate. Remove pressure plate, pump ring, vanes, retaining
ring, rotor and thrust plate assembly from body. Remove drive shaft.
Using a screwdriver, pry drive shaft oil seal from housing. Remove
dowel pins and seals.
Cleaning & Inspection
1) Clean all pump components in solvent, and blow dry.
Inspect flow control valve assembly for wear, scoring, burrs and other
damage. Inspect seal bore for burrs, nicks and score marks.
2) Inspect machined surfaces of body for scratches and burrs.
Check "O" ring mating surfaces. Inspect drive shaft for excessive
wear.
3) Inspect pump ring for roughness. Check thrust plate and
pressure plate for scoring and wear. Ensure vanes slide freely but fit
snugly into slots. If vanes are loose in slots, replace rotor and/or
vanes.
Reassembly
1) Before installation, coat all "O" rings, rotor, pressure

plate and end plate with petroleum jelly. Install new drive shaft seal
in housing. Install "O" ring in third groove of housing. Install dowel
pins in thrust plate. Install drive shaft through thrust plate and
rotor. Install NEW retaining ring. Ensure rotor slides freely on drive
shaft splines.
2) Install drive shaft in pump housing. Ensure thrust plate
engages with dowel pins. Install pump ring on dowel pins with rotation
arrow facing upward. Install vanes with rounded edges toward pump
ring.
3) Lubricate outer chamfered edge of pressure plate with
petroleum jelly. Install pressure plate with spring groove facing
upward. To seat pressure plate, place large socket on pressure plate
and press downward approximately 1/16".
4) Install end plate "O" ring in second groove of housing.
Install pressure plate spring and end plate in housing. Press end
plate downward, and install retaining ring. Install "O" ring, flow
control valve and spring.
5) Install mounting stud and pressure line union "O" rings in
rear of pump housing. Lubricate inner edge of reservoir with petroleum
jelly, and install. Install mounting stud. Tighten stud to
specification. Install pressure line union, and tighten to
specification. See appropriate table under TORQUE SPECIFICATIONS.
6) Using Pump Pulley Installer (J-25033-B), install pulley o\
n
pump shaft. Ensure shaft protrudes distance measured in disassembly
procedure.
7) When replacing plastic pulley with metal pulley, install
pulley flush with end of shaft. Install pump on engine, and compare
alignment with adjacent pulleys. If necessary, correct alignment by
using pump pulley installer to adjust shaft protrusion.
NON-SUBMERGED VANE POWER STEERING PUMP
Disassembly
1) Remove return tube. Clean exterior of unit. Measure
distance shaft protrudes through pulley, and record for reassembly
reference. Using pulley remover, remove pulley from shaft. Remove
fitting, "O" ring, flow control valve and spring. See Fig. 7.
2) Remove snap ring, drive shaft and bearing. Note direction
of snap ring installation for reassembly reference. Support drive
shaft bearing on inner race, and press drive shaft from bearing. Using
screwdriver, remove drive shaft seal from housing.
3) Insert punch into access hole to disengage and remove
retaining ring. Using a brass drift, tap on thrust plate, and remove.
Remove "O" ring, pump ring, rotor and vanes. Remove dowel pins,
pressure plate, "O" ring and pressure plate spring. Remove "O" ring,
dowel pin and sleeve.
Fig. 7: Exploded View of Cherokee & Comanche Pump Assembly
Courtesy of Chrysler Motors

Cleaning & Inspection
1) Clean all pump components in solvent, and blow dry.
Inspect flow control valve assembly for wear, scoring, burrs and other
damage. Inspect seal bore for burrs, nicks and score marks.
2) Inspect machined surfaces of body for scratches and burrs.
Check "O" ring mating surfaces. Inspect drive shaft and sleeve for
wear.
3) Inspect pump ring for roughness. Check thrust plate and
pressure plate for scoring and wear. Ensure vanes slide freely but fit
snugly into slots. If vanes are loose in slots, replace rotor and/or
vanes.
Reassembly
1) Lubricate all "O" rings, seals, pump ring, rotor and vanes
with petroleum jelly. Install sleeve. Ensure sleeve is fully seated.
2) Install "O" ring in sleeve seat. Install small dowel pin
in pump housing. Install pressure plate spring and "O" ring. Install
pressure plate with dowel pin hole aligned with dowel pin holes.
Install dowel pins.
3) Install pump ring with identification marks located
adjacent to one dowel pin. Install rotor with counterbore toward drive
shaft end of housing.
4) Install vanes with rounded edges toward pump ring. Install
thrust plate "O" ring. Install thrust plate with indentations aligned
with bolt holes of housing. Install retaining ring.
CAUTION: Pump ring must be installed with identification marks
located adjacent to dowel pins. Thrust plate must be
installed so indentations in thrust plate align with bolt
holes of housing and thrust plate engages with pump ring
dowel pins.
5) Using a socket, install drive shaft seal in housing until
seal bottoms. Support drive shaft bearing on inner race, and press
drive shaft into bearing. Install drive shaft and bearing in pump
housing.
6) Rotate drive shaft during installation to align with rotor
serrations. Ensure bearing is fully seated in pump housing. Snap ring
should be installed with large lug area (near snap ring pliers hole)
positioned right of small lug (near snap ring pliers hole), ensuring
beveled area of snap ring is properly positioned.
7) Install spring, flow control valve and "O" rings. Install
return tube with new "O" ring. Install pulley.
STEERING GEAR
Disassembly
1) Cap all openings in gear. Clean gear exterior thoroughly.
Mount gear in vise so that pitman shaft points downward. Rotate
housing end plug retainer ring until one end of plug is over the hole
in the housing.
2) Force end of ring from groove in housing and remove.
Rotate input shaft counterclockwise to force housing end plug out of
housing. Rotate input shaft clockwise 1/2 turn to draw rack/piston
inward. Remove piston end plug.
CAUTION: DO NOT rotate shaft more than is necessary to remove plug as
ball bearings will fall out of worm and rack piston assembly.
3) Remove lock nut from sector shaft adjuster. Remove sector
shaft cover. Remove and discard "O" ring from cover. Turn input shaft
until sector shaft teeth are centered in housing.

4) Tap end of sector shaft with a soft-faced hammer to free
shaft from housing, then remove sector shaft. Remove adjuster plug
lock nut. Remove adjuster plug with a spanner wrench.
5) Insert a rack/piston arbor into end of rack/piston until
arbor just contacts worm shaft. Turn stub shaft counterclockwise to
force rack/piston onto arbor. Remove rack/piston and arbor as an
assembly.
6) Take care to keep arbor fully inserted so ball bearings
will not fall out. Remove input shaft and control valve assembly from
housing. Remove worm, wormshaft lower thrust bearing, and races from
housing.
Reassembly
1) Lubricate all parts with clean power steering fluid before
reassembly. Install the lower thrust bearing and races onto the worm.
Cupped side of thrust washers must face toward stub shaft. See Fig. 8.
Fig. 8: Reassembly of Valve Body & Worm Shaft Assembly
NOTE: If conical thrust races are used, ensure tapered surfaces
are parallel to each other and that cupped sides face toward
stub shaft.

2) Install stub shaft cap "O" ring in valve body. Align valve
body drive pin on worm with narrow pin slot in valve body. Worm drive
lugs must engage in stub shaft cap.
3) Install valve body and worm assembly into housing. Perform
installation by pressing directly on valve body only. This will
prevent stub shaft "O" ring from disengaging from valve body.
4) Valve body is correctly seated when fluid return port in
housing is fully visible. Ensure worm locating pin is fully engaged in
valve body. Place seal protector over input shaft, install a new
adjuster plug "O" ring, then install adjuster plug.
5) Remove seal protector from housing and loosely install
adjuster plug lock nut. Insert arbor and rack/piston into housing.
Align worm and rack/piston and turn stub shaft clockwise to engage
worm. Maintain pressure on arbor until worm is fully engaged.
6) Turn input shaft clockwise until middle rack groove in
rack/piston is aligned with center of sector shaft roller bearing.
Remove arbor. Install a new sector shaft cover gasket.
7) Thread sector shaft cover onto adjuster screw until
bottomed. Back off 1 1/2 turns. Install sector shaft so that center
gear tooth meshes with center groove in rack/piston. Install cover
attaching bolts.
8) Install adjuster lock nut halfway onto sector shaft.
Install piston and plug in rack/piston. Install housing end plug "O"
ring, end plug and retainer ring. Adjust worm bearing preload and
over-center preload at this time.
ADJUSTER PLUG
Disassembly
1) Remove thrust bearing retainer ring with a screwdriver,
taking care not to score needle bearing bore. Discard retainer ring.
Remove thrust bearing spacer, thrust bearing and bearing races.
2) Remove and discard adjuster plug "O" ring, then remove
input shaft seal retainer. Remove and discard dust seal. Pry input
shaft seal from adjuster plug.
3) Inspect needle bearing in adjuster plug. If necessary,
remove bearing by pressing out from spacer end. See Fig. 9.
Inspection
Inspect thrust bearing for cracks and rollers for pitting,
scoring, or cracking. Check thrust races and spacer for damage or
damage. Replace parts as necessary.
Fig. 9: Exploded View of Adjuster Plug Assembly
Reassembly
1) Press roller bearing into adjuster plug (identification
end facing arbor) until bearing bottoms on input shaft seal bore.

Install input shaft seal with spring in seal facing adjuster plug.
2) Install dust seal into adjuster plug. Rubber face of seal
must face away from plug. Install retainer ring. Install adjuster plug
"O" ring.
3) Assemble thrust bearing, thrust bearing race, and thrust
bearing spacer on adjuster plug. Using a brass or wooden dowel, press
bearing retainer into needle bearing bore.
RACK/PISTON & WORM
Disassembly
Remove worm, lower thrust bearing and bearing races from rack
piston. Remove piston ring and back-up "O" ring from rack/piston.
Remove ball return guide clamp, ball return guide and all ball
bearings from rack/piston.
Inspection
1) Clean and dry all parts. Inspect worm and rack/piston
grooves for scoring. Inspect ball bearings for damage. If any ball
bearings are damaged, replace entire set. Check ball guides for
pinching of ends.
2) Inspect lower thrust bearing races for cracking, scoring,
or pitting. Replace wormshaft and rack/piston as an assembly if either
part is damaged. Inspect rack/piston teeth for chips, cracks, dents or
scoring.
Reassembly
1) Install "O" ring and piston ring onto rack/piston using
care not to twist them. Install worm into rack/piston until worm is
against piston shoulder. Install ball bearings into rack/piston while
slowly rotating worm counterclockwise.
NOTE: See RACK PISTON & WORM ASSEMBLY BALL BEARINGS table for
number of balls to be installed. BE SURE to install light
and dark colored balls alternately, as Black balls are
.0005" smaller than Silver balls.
2) Install correct number of balls in ball guide. Bearings in
guide must be in sequence with bearings in rack/piston. Hold balls in
place with chassis lubricant and install return ball guide assembly
into position.
3) Install clamp and tighten attaching bolts. Alternate light
and dark colored balls when installing. See Fig. 10. Insert
rack/piston arbor into rack/piston until it contacts worm. Maintain
pressure on arbor, and back worm out of rack/piston. DO NOT allow ball
bearings to drop out of circuits.
RACK PISTON & WORM ASSEMBLY BALL BEARINGS TABLE









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Application Rack/Piston Guide
Jeep ...................... 18 ....................... 6









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Fig. 10: Installing Ball Bearing into Rack/Piston Assembly
ROTARY VALVE
NOTE: Complete valve assembly is balanced during assembly. If
replacement of any part other than rings or seals is
necessary, replace complete assembly.
Disassembly
1) Remove and discard stub shaft cap "O" ring. Invert valve
and lightly tap end of stub shaft against wood block until shaft cap
is free of valve body. Pull stub shaft outward until drive pin hole is
visible. Depress the pin to remove the stub shaft from the valve body.
See Fig. 11 .
NOTE: DO NOT pull shaft any further than 1/4" (6 mm) or spool
valve may become cocked in valve body.

Fig. 11: Pulling Shaft from Valve Assembly
2) Disengage drive pin and carefully remove stub shaft from
valve body and spool assembly with a twisting motion. If binding
occurs, realign valve and try removal again.
CAUTION: DO NOT force stub shaft or spool out of valve body.
3) Remove spool valve from valve body with twisting motion.
Remove and discard all "O" rings and Teflon rings.
Fig. 12: Exploded View of Valve Body Assembly
Reassembly
1) Lubricate all valve body components with power steering
fluid. Install replacement back-up "O" rings in seal grooves and