Adjusting Worm Bearing Preload; Position Of Pitman Shaft And Ball Nut - Pontiac Grand Prix Service Manual

9-28
1969
PONTIAC SERVICE MANUAL
Fig. 9-53 Adjusting Worm Bearing Preload
steering shaft slightly to aid in installing balls) and
insert 6 balls in each return guide using petrolatum to
hold balls in place. Install return guide clamp and
screw.
CAUTION: Do not rotate worm shaft while installing
balls, since balls may enter crossover passage between
circuits. This will cause improper operation of ball nut.
3. Place upper bearing on worm shaft. Center ball nut
on worm, then slide worm shaft, bearing and nut into
housing.
4. Install adjuster in housing.
NOTE: Adjuster should be installed just tight enough to
hold bearing races in place. Install adjuster lock nut
loosely.
5. Slip flexible coupling assembly on shaft and turn
steering gear from one extreme to the opposite to
make certain there is no unusual binds and remove
coupling assembly.
Fig. 9-54 Position of Pitman Shaft and Ball Nut
NOTE: Never allow ballnut to strike en& of ball races
in worm due to possibility of damage to ball guides.
a. Using a 11/16"-12 point deep socket and inch
pound torque wrench, measure torque required to turn
worm shaft, keep wrench in motion when off high
point of gear. Torque required should be 7 lb. in.
b. If torque does not meet above specifications loosen
worm bearing adjuster lock nut (Fig. 9-53) and turn
adjuster to bring torque within 7 lb. in. limits.
c. Tighten lock nut and recheck torque.
d. Remove 11/ 16" socket and torque wrench.
6. Install pitman shaft adjusting screw and selective
shim in pitman shaft (Fig. 9-50).
NOTE: Screw must be free to turn, but have no more
than .002" end play. If end play of screw in slot is too
'
tight or too loose, select new shim to .give proper
clearance. Shims are furnished in four thicknesses:
.063", .MY', .067", and .069".
7. Position pitman shaft seal on pitman shaft and seat
seal using suitable socket as a driver.
6
8. ~nstall pitman shaft and adjusting screw with sector
and ball nut teeth positioned as shown in Fig. 9-54.
9. Install side cover and gasket on adjusting screw,
turning screw counterclockwise until it projects through
side cover 5/8" to 3/4".
10. Install two cover attaching bolts. Tighten to 35 lb.
ft. torque.
11. Tighten pitman shaft adjusting screw so that teeth
on shaft and ball nut engage but do not bind. Final
adjustment will be made later.
12. Fill steering gear with all-season steering gear
lubricant and install third cover attaching bolt.
Tighten to 35 lb. ft. torque.
13. Adjust overcenter and/or pitman shaft backlash as
follows:
a. Place a 11/16"-12 point socket and lb. in. torque
wrench over end of worm shaft.
b. Tighten pitman shaft adjusting screw as necessary
to obtain a reading of 7 lb. in. torque, in excess of total
thrust bearing preload, and seal drag, when the worm
gear is turned through the center (high point) (Fig.
9-55). Total thrust bearing adjustment, and seal drag
not to exceed 16 lb. in. The highest reading should not
fall outside 1 /8 turn each side of center.
c. Tighten pitman shaft adjusting screw lock nut to 23
lb. ft. torque and recheck adjustment.