Pitman Shaft Seal Replacement; Steering Gear Adjustments - GMC 1986 P-Truck Service Manual

3B3-16 POWER STEERING
3. Pitman arm. Refer to STEERING LINKAGE (SEC.
3B1).
• Remove the plugs and caps from the steering
gear and hoses.
4. Hoses to the steering gear. Torque hose fittings to
" Specifications" at the end of this section.
PITMAN SHAFT SEAL
REPLACEMENT
+ + Remove or Disconnect
Tools Required:
J-29107 Pitman Arm Puller.
J-4245 Internal Snap Ring Pliers.
Mark the position of the pitman arm to the pitman
shaft. Remove the pitman arm using J-29107.
Refer to STEERING LINKAGE (SEC. 3B1).
Position a drain pan under the steering gear.
.
1 Retaining ring using J-4245.
Start the engine and full turn the steering wheel
to the left-turn position for one or two seconds at
a time. This will force the pitman shaft seals and
washers out of the housing.
Stop the engine.
Pitman shaft seals and washers from the pitman
shaft.
L*
Inspect
• Pitman shaft seal surfaces for roughness or
pitting. If pitted, replace the shaft.
• Housing for burrs. Remove the burrs before
installing the new seals.
jQ * Clean
• Pitman shaft and seal areas using a crocus cloth.
-n - Install or Connect
Tools Required:
J-6219 Steering Gear Pitman Shaft Oil Seal
Installer.
J-4245 Internal Snap Ring Pliers.
Lubricate the new seals with power steering fluid.
Apply a single layer of tape to the pitman arm
shaft to avoid damaging the seals.
Single lip seal and washer use J-6219. Install far
1
.
enough to provide clearance for the remaining
seal, washer and retaining ring. DO NOT allow
the seal to bottom on the end of the counter bore.
Double lip seal and washer use J-21553.
Retaining ring use J-4245.
Pitman arm. Refer to STEERING LINKAGE (SEC.
3B1).
STEERING GEAR
ADJUSTMENTS
Im portant
• Before any adjustments are made to the steering
gear, refer to " Diagnosis of Power Steering
System" for reviewing the possible steering
system problems.
The steering gear adjustment is made only as a
correction and not as a periodic adjustment. Adjusting
the steering gear in the vehicle is NOT recommended
for two reasons:
1. The complexity involved in adjusting the worm
thrust bearing preload.
2. The friction effect provided by the hydraulic fluid
in the steering gear.
For proper adjustment, remove the steering gear
from the vehicle. Drain the power steering fluid from
the gear. Mount the gear in a vise and make the
following adjustments.
The steering gear requires two adjustments which
are: the worm thrust bearing preload and the pitman
shaft over-center preload adjustment.
The worm thrust bearing preload is controlled by the
amount of compression force exerted on the conical
worm bearing thrust races by the adjuster plug.
The pitman shaft over-center preload is controlled by
the pitman shaft adjuster screw which determines the
clearance between the rack piston and the pitman
shaft sector teeth.
Im portant
Adjust the worm thrust bearing preload first,
then adjust the pitman shaft over-center
preload.
Worm Bearing Preload
Adjust (Figures 1, 2, 9 through 13)
Tool Required:
J-7624 Adjustable Spanner Wrench.
1. Loosen and remove the adjuster plug nut (6)
(figure 9).
2. Turn the adjuster plug (3) in (clockwise), using
J-7624, until the plug and thrust bearing are firmly
bottomed in the housing.
• Adjuster plug to 27 N m (20 ft. lbs.).
3. Place an index mark on the housing even with
one of the holes in the adjust plug (figure 10).