Pontiac FIREBIRD 1972 Service Manual page 1224

STEERING 9-7 1
4. Replace pitman shaft assembly if teeth are damaged
or if the bearing surfaces are pitted or scored.
5. Check pitman shaft lash adjusting screw. It must be
free to turn with no perceptible end play. If adjusting
screw is loose replace the pitman shaft assembly.
ASSEMBLY
Thread the side cover onto the pitman shaft adjusting
screw until it bottoms and then turn in 1/2 turn. Install
a new adjusting screw locknut, but do not tighten.
B E INSTALLED
UNDER PISTON
RACK-PISTON
RACK-PISTON
CLEANING AND INSPECTION
1. Wash all parts in clean solvent and dry with com-
pressed air.
2. Inspect the worm and rack-piston grooves and all the
balls for scoring. If either the worm or rack-piston
needs replacing, both must be replaced as a matched
assembly.
3. Inspect ball return guide halves, making sure that the
ends where the balls enter and leave the guides are
not damaged.
4. Inspect lower thrust bearing and washers for scores
or excessive wear. If any of these conditions are
found, replace the thrust bearing and washer.
5. Inspect rack-piston teeth for scoring or excessive
wear. Inspect the external ground surfaces for wear,
scoring or burrs.
ASSEMBLY
1. If the plastic oil seal and " 0 " ring were removed,
lubricate a new " 0 " ring and seal with power steering
fluid and install in groove on rack-piston.
NOTE: The plastic ring may be slightly loose
after assembly, but will tighten up when sub-
jected to the hot oil in the system (Fig, 9-96).
2. Slide the worm all the way into the rack-piston.
NOTE: It is not necessary to have the thrust
beanng assembly on the worn at this time.
3. Turn the worm until the worm groove is aligned with
the lower ball return guide hole (Fig. 9-97).
Fig. 9-96 Installing Plastic Ring on Rack-Piston
4. Lubricate the balls with power steering fluid, then
feed 17 balls into the rack-piston, while slowly rotat-
ing the worm counterclockwise.
CAUTION: The black balls are . m 5 " smaller
than the silver balls. The black and silver balls
must be installed alternately into the rack-pis-
ton and return guide.
5. Alternately install 7 balls (black and silver) into the
return guide and retain with grease at each end of
guide.
6. Install the return guide assembly onto the rack-pis-
ton.
7.
Install the return guide clamp and tighten the 2
clamp screws to 10-lb. ft. torque.
COUNTER CLOCKWISE
Fig. 9-97 Installing Balls in Rack-Piston