Steering Gear Adjustments - GMC G Service Manual

Figure 14 — Installing Pitman Shaft Seals

STEERING GEAR ADJUSTMENTS

] Important
• Before any adjustments are made to the steering
gear, refer to "Diagnosis of Power Steering System"
for reviewing the possible steering system
problems.The steering gear adjustment is made only
as a correction and not as a periodic adjustment.
Adjusting the steering gear in the vehicle is NOT rec­
ommended for two reasons:
1. The complexity involved in adjusting the worm thrust
bearing preload.
2. The friction effect provided by the hydraulic fluid in the
steering gear.
For proper adjustment, remove the steering gear from
the vehicle. Drain the power steering fluid from the gear.
Mount the gear in a vise and make the following
adjustments.
The steering gear requires two adjustments which are:
the worm thrust bearing preload and the pitman shaft over­
center preload adjustment.
The worm thrust bearing preload is controlled by the
amount of compression force exerted on the conical worm
bearing thrust races by the adjuster plug.
The pitman shaft over-center preload is controlled by the
pitman shaft adjuster screw, which determines the clear­
ance between the rack piston and the pitman shaft sector
teeth.
POWER STEERING 3B3-17
I T I Important
• Adjust the worm thrust bearing preload first,
then adjust the pitman shaft over-center
preload.
Worm Bearing Preload
\ S \ Adjust (Figures 1, 2, and 15 through 19)
Tool Required:
J 7624 Adjustable Spanner Wrench.
1. Loosen and remove the adjuster plug nut (6) (figure
15).
2. Turn the adjuster plug (3) in (clockwise), using
J 7624, until the plug and thrust bearing are firmly bot­
tomed in the housing.
IC il Tighten
• Adjuster plug to 27 N»m (20 ft. lbs.).
3. Place an index mark on the housing even with one of
the holes in the adjuster plug (figure 16).
4. Measure back (counterclockwise) 4.7-6.3 mm (3/16-
1/4-inch) from the index mark and mark the housing
(figure 17).
5. Rotate the adjuster plug back (counterclockwise)
using J 7624 until the hole in the plug is aligned with
the second mark on the housing (figure 18).
6. Install the adjuster plug nut (6).
H O Tighten
• Nut to "Specifications" at the end of this section.
Be sure the adjuster plug does not turn when
tightening the nut.
7. Use an inch-pound torque wrench and a 12-point
deep socket to measure the required torque to turn
the stub shaft (4). Take the reading with the handle of
the torque wrench near the vertical position. Turn the
stub shaft to the right stop and then back (counter­
clockwise) 1/4 turn at an even rate (figure 19). Record
the torque reading.