Pontiac FIREBIRD 1972 Service Manual page 1209

9-56 1972 PONTIAC SERVICE MANUAL
MAJOR SERVICE
ADJUSTMENT PROCEDURES (ON
BENCH)
Correct adjustment of the steering gear is extremely im-
portant. Before any adjustments are made to the steering
gear in an attempt to correct such conditions as shimmy,
hard to loose steering and road shocks, a careful check
should be made to determine that front end elignment,
shock absorbers, wheel balance and tire pressure are cor-
rectly adjusted and/or operating satisfactorily.
There are two adjustments on the recirculating ball-type
steering gear:
1. Worm bearing preload adjustment.
2. Overcenter or Pitman Shaft (Lash) Adjustment.
CAUTION: It is very important that adjost-
ments be made in above sequence to avoid
steenhg gear damage.
WORM BEARING PRELOAD
1. Tighten the adjuster plug until all end play has been
removed and then loosen one-quarter turn.
2. Using an 11/16" 12-point socket and 25 pound inch
torque wrench, carefully turn the wormshaft all the
way to the right comer and then turn back about
one-half turn.
3. Tighten the adjuster plug until the proper thrust
bearing preload is obtained (5-8 lb. in.).
4. Tighten the adjuster plug locknut to 85 lb. ft. torque.
OVERCENTER OR PITMAN SHAFT (LASH)
Turn the wormshaft from one stop all the way to the
other, counting the number of turns. Then turn the
shaft back exactly half the number of turns to the
center position.
Turn the pitman shaft lash adjuster screw clockwise
to remove all lash between the ball nut and sector
teeth. Tighten the locknut to 23 lb. ft. torque.
Again using the 11/16" 12-point socket and a 25
pound inch torque wrench, observe the highest read-
ing while the gear is turned through center position.
Reading should be 4-10 lb. in. in excess of worm
bearing preload.
NOTE: Total worn bearing preload adjostment
andpitman shaft adjostment should not exceed
16 lb. in.
4. If necessary, readjust lash adjuster screw to obtain
proper torque. Tighten the locknut to 23 lb. ft. torque
and again check torque reading through center of
travel.
DISASSEMBLY
As with any ball beaning unit the steeringgearparts must
be kept free of dirt (Fig. 9-68). Clean paper or rags should
be spread on the workbench before starting disassembly of
the steering gear.
1. Place the steering gear in a vise, clamping onto one
of the mounting tabs. The wormshaft should be in a
horizontal position.
2. Rotate the wormshaft with flexible coupling from
stop to stop, counting the total number of turns. Then
turn back exactly halfway, placing the gear on center.
3. Remove the three self locking bolts attaching the side
cover to the housing.
4. Tap lightly on the end of the pitman shaft with a
pastic hammer and lift the side cover and pitman
shaft assembly from the gear housing (Fig. 9-69).
NOTE: If the pitman shaft sector does not clear
the opening in the housing easily, turn the
wornshaft by hand until the sector will pass
through the opening in the housing.
5. Scribe a mark on flexible coupling and worm shaft.
Remove coupling form shaft.
6. Loosen worm bearing adjuster lock nut with brass
drift.
7. Remove the adjuster plug assembly. This includes
one wormshaft bearing and race.
8. Draw the wormshaft and ball nut assembly from
housing (Fig. 9-70).
CAUTION: Use care that the ball nut does not
run down to either end of the worm. Damage
will be done to.the ends of the ballguides if the
nut is all0 wed to rotate until stopped at the end
of the worn.
9. Remove the remaining worm bearing from either the
wormshaft or from inside the gear housing.
10. Where applicable use a suitable size screw driver to
pry the lower bearing retainer from the adjuster plug
housing and remove the bearing (Fig. 9-71).