Pontiac tempest 1968 Service Manual page 591

9-34
1968 P O N T I A C SERVICE M A N U A L
CA UTION: Do not use solvent on oil seals and O -
vings which are going to be replaced (Fig. 9-60).
INSPECTION OF PITMAN SHAFT GEAR
AND SIDE COVER
1. Inspect pitman shaft bearing surface in side
cover for excessive wear or scoring. If badly worn
or scored, replace side cover and bushing assembly.
2. Check pitman shaft sector teeth, bearing and
seal surfaces and replace if badly worn, pitted or
scored.
3
0
Check lash screw for end play.
If end play is noticed in step 3 , replace pitman
shaft gear assembly.
INSPECTION OF RACK-PISTON NUT AND WORM
1. Inspect worm and rack-piston nut grooves and
all of the balls for excessive wear or scoring. If
either the worm or rack-piston nut needs replacing,
both must be replaced as a matched assembly.
2. Inspect ball return guides, making sure that
ends where balls enter and leave guides are not
damaged.
3. Inspect lower thrust bearing and races for
excessive conditions of wear, pitting, scoring or
cracking. If any of these conditions are found, re­
place the thrust bearing and races.
4. Inspect rack-piston nut teeth for pitting, wear,
and scoring.
5. Inspect outside surface of rack-piston nut for
wear, scoring or burrs.
6. Inspect thrust bearing rollers and races for
excessive conditions of wear, pitting, scoring, crack­
ing, or brinelling. If any of these conditions are
found, replace the thrust bearing assembly.
INSPECTION OF ROTARY VALVE
1. If there was evidence that the torsion bar to
stub shaft O- ring seal has been leaking (oil leak be­
tween the stub shaft and torsion bar at the stub shaft
coupling flange), the entire rotary valve assembly
should be replaced.
2
0
If any part of parts of the rotary valve assem­
bly (including stub shaft assembly) are badly worn,
cracked, pitted or broken, the entire rotary valve
assembly should be replaced. A slight polishing on
the valving surfaces is normal.
INSPECTION OF GEAR HOUSING
1. Inspect gear housing for any defects in the
piston bore or the rotary valve bore. Inspect all re­
taining ring grooves and seal surfaces for scratches
or nicks. If any major defects are found, the housing
should be replaced.
NOTE: A slight polishing of the cylinder bore by
the piston is not uncommon and does not affect the
operation of the gear.
2. Inspect ball plug in the housing, if leaking or
raised above the housing surface, drive in flush to
1/16" below surface. The ball plug can be tight­
ened by staking housing. Housing should be re­
placed only if leaks in this area cannot be properly
sealed.
Clean area of leak with solvent and/or a wire
brush. Dry thoroughly and apply a liquid sealant
which will flow into the area between the ball plug
and the housing and then harden. Devcon "B" or
equivalent (commercially available products) should
seal such leaks.
3. Inspect the connectors. If badly brinelled or
scored, replacement will be necessary.
4. Inspect pitman shaft gear needle bearing; if
worn or pitted, replace.
ASSEMBLE OF STEERING GEAR
Lubricate all parts as they are assembled.
ASSEMBLE PITMAN SHAFT GEAR
AND SIDE COVER
1. Screw lash adjuster through side cover until
cover bottoms on pitman shaft gear.
2. Install lash adjuster lock nut while holding lash
adjuster with 7/32" alien wrench do not tighten
lock nut.
ASSEMBLE ROTARY VALVE
1. Assemble one valve body Teflon ring back-up
O-ring seal in each groove on valve body. Do not
allow seals to become twisted.
2. Assemble valve Teflon rings in ring groove
over O- ring seals by carefully slipping rings over
valve body. Rings may appear loose or twisted in
grooves, but heat of oil after assembly will cause
them to straighten.
3 . Install valve spool dampener O-ring seal in
valve spool groove, then lubricate seal in Type A
hydraulic fluid. Do not allow seal to twist in groove.
4. Assemble stub shaft assembly in valve body
aligning groove in valve cap with pin in valve body
(Fig. 9-56)
0
Press on cap until cap is against
shoulder in valve body with valve body pin in cap
groove. Hold these parts together during remainder
of assembly.