Hummer H1 Service Manual page 405

6-22 Wheels and Tires/Central Tire Inflation System (CTIS)
WHEEL ALIGNMENT
Check alignment on a rack with the front tires in the straight-
ahead position and inflated to manufacturer's recommended
pressure.
Preliminary Inspection
1. Check tire condition, tread wear (Figure 6-27), run-out,
and inflation.
2. Raise and support vehicle so wheels are free to rotate.
Then secure the steering wheel in straight-ahead position.
3. Check tie rods and upper control arms for distortion, play,
or looseness (Figure 6-38). Replace worn, damaged parts
before proceeding.
NOTE: If the vehicle was previously lifted off the ground for
other service, center the steering wheel, roll the vehicle for-
ward and back to settle the suspension and relieve the tension
on the ball joints before beginning checking procedure.
CONTROL ARM
BUSHING
UPPER
CONTROL ARM
CONTROL
BUSHING
ARM
TIE ROD
STABILIZER
BAR
Figure 6-38: Suspension Inspection Components
4. Check upper ball joints: With the vehicle on the ground
(being careful not to damage the boot), place the tip of a
prybar between the steering knuckle and the ball joint boot
(Figure 6-39). With the shank of the prybar contacting the
upper control arm as shown, pry upward and note the
movement of the ball joint against a ruler. Be careful to
measure only the ball joint movement and not the flex of
the control arm resulting from prying against it. Any upper
ball joint with more than 1/16" (1.6 mm) movement
should be replaced.
5. Check geared hubs for spindle end play or side-to-side
movement by grasping the edge of the tire and attempting
to move the tire up and down.
NOTE: If any spindle movement is apparent, adjust the spin-
dle bearings.
_______________
UPPER
BALL JOINT
GEARED HUB
LOWER
BALL JOINT
®