Hummer H1 (2002+). Manual - part 129

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Steering System 8-23

05745159

13. Turn steering wheel lightly against each stop and record

maximum pressure.

If pressure at each stop is about the same as recorded
in step 10, and flow drops to 0.5 gpm (1.85 L/min.),
continue with test.

If pressures does not reach maximum recorded in step
10, and flow rate does not fall off, overhaul steering
gear to correct internal leakage in valve, or past seal
rings.

14. Turn steering wheel to the right, release it., and observe

the analyzer gauge. Then turn the wheel to the left, release
it, and observe the gauge again.

If the gauge needle indicates normal pressure then
snaps back as the wheel is released. Continue the test.

If the gauge indicates normal pressure but the needle
is slow to return when the wheel is released, the steer-
ing gear valve body or spool is sticking. Overhaul will
be required to correct the problem.

15. If gear and pump test OK but a problem still exists, check

for fluid contamination. Draw off sample with suction gun
and empty sample in glass container. Look for burned
fluid, foreign material, fluid layering (fluid separates into
two layers), foreign material/metal particles in the fluid.
Any of these conditions will cause gear and pump
problems. Flushing the system with new fluid may correct
the problem.

16. If fluid condition is OK but a problem still exists, a

problem may exist in the steering linkage, tires/wheels, or
suspension part. Further diagnosis will be required.

Figure 8-30: Analyzer Pressure Test Connections

POWER STEERING GEAR DISASSEMBLY AND
OVERHAUL

Cleanliness is extremely important to a successful gear over-
haul. Clean the gear exterior before disassembly and make sure
the workbench area is clean and dry. Drain as much of the old
fluid from the gear as possible beforehand. Dirt and foreign
material must not be allowed to enter the gear internal compo-
nents. Use lint free shop towels for wiping parts and hands
clean. Lint from cotton towels will flow through the system
and eventually cause the valve body spool, or pump control
valve to stick and bind.

Side Cover and Pitman Shaft Removal

Remove side cover attaching bolts.

Hold adjuster screw with hex wrench and remove adjuster
screw nut.

Rotate stub shaft as necessary to center pitman shaft teeth
in rack piston. Use 12 point socket and ratchet to turn stub
shaft.

Remove pitman shaft, side cover, and gasket (Figure 8-31).

Figure 8-31: Side Cover and Sector Shaft

FITTING

ANALYZER

ADAPTERS

J-25323

ADJUSTER

SIDE

GASKET

PITMAN

ADJUSTER

LOCKNUT

SHAFT

COVER

SCREW

4-1-00

8-24

Steering System

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Gear Housing End Plug Removal

Rotate end plug retaining ring until one end is under small
access hole in housing (Figure 8-32).

Figure 8-32: End Plug Retaining Ring Removal

Unseat end plug retaining ring with small pin punch and
screwdriver (Figure 8-32). Insert punch through access
hole in housing as shown.

Slowly rotate stub shaft counterclockwise to ease end
plug out of housing.

CAUTION:

Do not rotate the stub shaft any farther than nec-

essary. The recirculating balls can drop out of the rack piston
and fall inside the piston chamber making further disassembly
extremely difficult.

Remove end plug (Figure 8-33).

Remove O-ring seal from housing (Figure 8-33).

Figure 8-33: End Plug and Seal Removal

Adjuster Plug Removal and Disassembly

Remove adjuster plug locknut with punch and hammer
(Figure 8-34).

Figure 8-34: Adjuster Plug Locknut Removal

Remove adjuster plug from housing with spanner wrench
J–7624 (Figure 8-35).

PUNCH

RETAINING RING

SCREWDRIVER

RETAINING

END

O-RING

GEAR

RING

PLUG

HOUSING

PUNCH

ADJUSTER

PLUG

LOCKNUT

4-1-00

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Steering System 8-25

05745159

Figure 8-35: Adjuster Plug Removal

Remove thrust bearing retainer by prying it up and out at
raised point on retainer (Figure 8-36).

Figure 8-36: Adjuster Plug Thrust Bearing

Retainer Removal

Remove bearing spacer, thrust bearing and races, and O-
ring (Figure 8-37).

Figure 8-37: Adjuster Plug Components

Remove stub shaft seal retainer.

Remove dust seal and oil seal (Figure 8-38). Use tool
J–6221 to remove seals.

Figure 8-38: Stub Shaft Bearing Removal

Remove stub shaft bearing with tool J–6221 (Figure 8-38).

SPANNER

ADJUSTER PLUG

TOOL

J–7624

SPACER

RAISED SECTION

OF RETAINER

SCREWDRIVER

SNAP

STUB SHAFT

O-RING

INNER

THRUST

OUTER

RETAINER

ADJUSTER

STUB

SHAFT

BEARING

PLUG

RACE

BEARING

SPACER

RACE

SEAL

RING

OIL SEAL

DUST SEAL

TOOL J–6221

STUB

ADJUSTER

PLUG

SHAFT

BEARING

4-1-00

8-26

Steering System

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Rack Piston Removal and Disassembly

Rotate stub shaft counterclockwise until rack piston is
even with seal groove in open end of housing. Do not
allow the rack piston to extend out of the housing. It only
needs to be about 1/4 inch from the end.

Remove rack piston plug (Figure 8-39). Use a ratchet and
socket extension to remove the plug as shown.

Figure 8-39: Rack Piston Plug Removal

Insert arbor tool J–21552 into rack piston (Figure 8-40).

Figure 8-40: Rack Piston Removal

Hold arbor tool tightly in rack piston and turn stub shaft
counterclockwise to push rack piston out of housing. Then
remove rack piston, and arbor tool as assembly
(Figure 8-40).

Remove wormshaft if it came out of stub shaft
(Figure 8-41).

Figure 8-41: Wormshaft Removal

Remove thrust bearing and races from wormshaft.

Remove teflon seal rings and backup O-rings from rack
piston (Figure 8-42).

Figure 8-42: Rack Piston Components

Remove bolts attaching recirculating ball guide halves to
rack piston, remove guides, and remove bearings from
rack piston (Figure 8-41). A total of 24 bearings are used;
12 chrome and 12 black.

EXTENSION

PISTON

RATCHET

RACK

PISTON

PLUG

RACK PISTON

ARBOR TOOL

J–21552

ARBOR TOOL

RACK PISTON

WORMSHAFT

J–21552

TEFLON

RACK

BEARING

BALL GUIDES

BALL

O-RING

SEAL

GUIDE

CLAMP

RING

PISTON

BALLS

4-1-00

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