Pontiac FIREBIRD 1972 Service Manual page 1216

STEERING
Since a handling stability complaint can be caused by
improperly adjusted worn thrust bearings as well as an
improper gear over-center @itman shaft lash) adjustment,
it is necessary that the steeringgear assembly be removed
from the vehicle and both thrust bearing and over-center
preload be checked and corrected as necessary. An in-
vehicle check of the steenng gear will not pin-point a
thrust beanng adjustment error.
INITIAL CHECKS
1. Remove gear from vehicle (see STEERING GEAR
-
REMOVE).
2. Drain oil from gear by rotating through its travel
several times.
3. Check gear adjustment torque as removed from car
as follows:
a. One-half turn off right and left stops.
b. One-half turn off center-right and left.
c. Over center (rotate through an arc 180 degress
each side of center)
-
right and left.
WORM THRUST BEARING ADJUSTMENT
1. Loosen pitman shaft (lash) adjuster screw lock nut.
2. Back off pitman shaft lash adjuster screw 1-1/2 turns
and retighten lock nut.
3. Loosen thrust bearing adjuster plug lock nut.
r
Torque Wrench
Fig. 9-79 Adjusting Thrust Bearing Preload
4. Back off thrust bearing adjuster plug 1/2 turn and
retighten lock nut.
5. Turn gear stub shaft to right stop and then back 1/2
turn.
6. Using a 25 pound inch torque wrench on gear stub
shaft, measure drag torque.
7. Tighten adjuster plug until torque to turn stub shaft
is 3 to 4 lb. in. greater than drag torque (with lock nut
tightened). See Fig. 9-79.
NOTE: Preload torque tends to drop o f f when
the Iock nut is tightened. Therefore, torque
reading must be taken with the Iock nut tight.
PITMAN SHAFT (LASH) OVER-CENTER
ADJUSTMENT
1. With gear on center, loosen pitman shaft (lash) ad-
juster screw lock nut and tighten pitman shaft lash
adjuster screw. Retighten lock nut (holding lash ad-
juster screw to keep it from turning) and measure
gear over-center torque at stub shaft. When checking
over-center torque, torque wrench should be rotated
through a 180 degree arc either side of center and
readings taken going over-center. Continue adjusting
lash adjuster screw and checking over-center torque
(with lock nut tightened) until correct over-center
torque is obtained. See Fig. 9-80. Limits for new and
old gears are different, as follows:
a. New Gear: Over-center torque to be 4-8 lb. in.
additional torque, but total over-center torque
must not exceed 18 lb. in.
Fig. 9-80 Pitman Shaft Over-Center Adjustment