GMC 1976 ZEO 6083 Maintenance Manual page 568

9- 3 6 STEERING
Figure 54-Installing Rack-Piston
torque . Torque reading should be between 4 and 6 in .
lbs. If torque is not within these specifications, loosen
lock nut and turn the adjuster until the proper torque
is obtained . Retighten nut as described in 4e . With
adjuster secured in place, coat junction of dust seal
and stub shaft with anhydrous calcium based grease
(included with repair kits).
5. Install the rack-piston as follows:
a. Lubricate the rack-piston teflon seal with
Power Steering Fluid.
b. Position Seal Compressor J-7576 against
the shoulder in the housing .
c. With Ball Retainer J-7539 in place in the
rack-piston, push the rack-piston (with teeth toward
pitman shaft opening), into the housing until Tool
J-7539 contacts the center of worm (figure 54).
d. Turn the stub shaft clockwise with a 3/4"
twelve point socket or box end wrench to thread the
rack-piston onto the worm while holding Tool J-
7539 against the end of the worm .
e.
When the rack-piston is completely
threaded on the worm, remove Ball Retainer J-7539
and Seal Compressor J-7576 .
6. Install the pitman shaft and side cover as fol-
lows :
a . Install a new "O" ring in the side cover and
retain with heavy grease .
b. Turn the stub shaft until the rack-piston
teeth are centered in the pitman shaft opening, then
install the pitman shaft and side cover so that the
center tooth of thepitman shaft engages the center
groove of the rack-piston.
c. Install the side cover bolts and tighten to 45
foot pounds .
7. Install the rack-piston plug in the rack-piston
and torque to 75 foot pounds .
8 . Install a new housing end cover "O" ring and
lubricate it with Power Steering Fluid. Install the
end cover and retaining ring .
9. Adjust the over-center preload as follows:
a. Make sure the over-center adjusting screw
is backed all the way out. Then turned back in 1/2
turn .
b. Install an inch-lb. torque wrench with a
3/4" 12-point socket on the stub shaft splines.
c. Rotate the stub shaft from one stop to the
other. Count the number of turns and locate the
center of travel, then check the combined ball and
thrust bearing preload by rotating the torque wrench
through the center of travel . Note the highest read-
ing.
d. Tighten the pitman shaft over center ad-
justing screw until the torque wrench reads 4-8 in .
lbs. (for a "new" gear) or 4-5 in . lbs. (for an "old"
gear) higher than the reading noted in step c. The
total reading should not exceed 20 in . lbs. (for a
"new" gear) or 16 in . lbs. (for an "old" gear).
e. While holding the adjusting screw, tighten
the locknut to 35 foot pounds using Adapter J-5860
(figure 55) and recheck the adjustment .
Figure 55-Torquing Over-Center Locknut