Hummer H1 (2002+). Manual - part 100

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Wheels and Tires/Central Tire Inflation System (CTIS) 6-15

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Figure 6-25: Runflat Assembly

Position wheel on tire machine with outside facing up.
Lubricate tire beads and mount inside tire bead on wheel.
Ensure “SIDE FACING OUTWARDS” lettering faces up
on GSA tires.

Install the right and left square nuts in the recesses of one
pair of runflat ends. When looking across the runflat to the
opposite side, the “R” square nut should be in the right
recess and the “L” square nut in the left recess
(Figure 6-25).

Start the cross bolt in one of the square nuts, then in the
second nut and tighten until there is full engagement in
both nuts. The thread engagement must be equal in both
nuts.

Using a bead spreader, insert the runflat halves in the tire.

Align the gap between the second pair of runflat ends with
one of the positioning fences on the wheel.

Assemble the second pair of runflat ends as in steps 3 and 4
and adjust the gap between the runflat ends to 53/64" (21
mm).

NOTE: The distance between the two runflat end gaps must
remain equal to reduce the risk of imbalance.

Verify that the positioning fences are centered in the
runflat end gaps and the gaps are equal.

Torque both cross bolts to 22 lb-ft (30 N•m) and install
cross bolt locking clips, screws and washers.

10. Torque the locking clip screws to 30-35 lb-in (4-5 N•m).

11. Lubricate tire bead and mount tire bead on the wheel.

NOTE: Before installing a new tire inspect tire sidewalls for a
“paint dot.” Paint dots are often painted on tires to indicate the
tire’s light spot for balancing purposes and may be located on
either side of the tire. If paint dot is present, position tire on
wheel so that paint dot is aligned with air valve on wheel. If
paint dot is not on air valve side of tire, reference paint dot
from other side of tire for proper positioning with air valve.

WARNING: Always use a tire inflation cage for infla-
tion purposes. Stand one side of cage during inflation,
never directly in front. Keep hands out of the cage dur-
ing inflation. Inflate assembly to recommended pres-

00-S06-013

LOCKING

CLIP

21 MM

RETAINING

SCREW

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Wheels and Tires/Central Tire Inflation System (CTIS)

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sure using a clip-on air chuck. Do not exceed 50 psi
(345 kPa) cold inflation pressure. Failure to follow
these instructions may result in serious injury or death.

12. Before installing valve core, inflate tire to seat beads. Use

of tire bead seater may be required.

13. Install valve core, inflate tire to recommended tire

pressure and install valve cap.

14. Check for leaks around wheel edges, insert, and air valve

with soapy solution.

15. Balance wheel/tire assembly with 15 oz. maximum

weight. Refer to tire balance procedure in service manual
if necessary.

16. Install wheel/tire assembly on vehicle.

Roll wheel/tire assembly to the vehicle.

Place the wheel/tire assembly on the geared hub
spindle studs.

Start the lug nuts by hand.

Snug the lug nuts.

Lower the vehicle.

Torque the lug nuts evenly and sequentially to 110 lb-
ft (149 N•m) (Figure 6-26).

If the vehicle is equipped with CTIS perform these additional
steps:

Lubricate the threads on the CTIS fitting with teflon
pipe sealant.

Install the fitting in the geared hub spindle.

Engage the quick disconnect fittings on all four
wheels.

17. Install the center cap.

Figure 6-26: Lug Nut Tightening Sequence

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Wheels and Tires/Central Tire Inflation System (CTIS) 6-17

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Inspecting Tire Tread Wear

Tire tread wear is a good indicator of tire balance and suspen-
sion condition. Unbalanced tires often cause cupped or scal-

loped tread wear patterns (Figure 6-27). Tire wear inspection
should be performed for all vibration complaints. Resolve tire
wear problems before continuing with diagnosis.

Figure 6-27: Tire Wear Patterns

RIGHT

FRONT

UNDERINFLATION

OVERINFLATION

MULTI-PROBLEM

RIGHT

FRONT

TOE-IN WEAR

CAMBER WEAR

OR CORNERING

TOE-OUT WEAR

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Wheels and Tires/Central Tire Inflation System (CTIS)

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WHEEL AND TIRE BALANCING

General

There are two types of tire and wheel balancing: static and dy-
namic. Static balance is the equal distribution of weight around
the wheel circumference. Wheels that are statically unbalanced
cause a bouncing action called vehicle shake and possible
steering nibble or oscillation. This condition will eventually
cause uneven tire wear (Figure 6-28).

Figure 6-28: Static Imbalance Correction

Dynamic balance is the equal distribution of weight on each
side of the centerline, so that when the wheel spins there is no
tendency for it to move from side to side. Wheels that are dy-
namically unbalanced may cause wheel shimmy, vehicle shake
or a steering wheel vibration called nibble or oscillation
(Figure 6-29).

Figure 6-29: Static Imbalance Correction

NOTE: Most electronic off-vehicle balancers are more accu-
rate than on-vehicle spin balancers. They are easy to use and
give a dynamic (two-plane) balance. On-vehicle balancing is
not recommended. When balancing off-vehicle, the wheel
should be mounted to the balancer with a cone through the
back side of the center pilot hole or by the wheel (spindle) stud
holes. The spindle stud method is recommended for CTIS
wheels.

Balancing

Remove wheel and tire assembly from the vehicle.

WARNING: Remove all stones and foreign material
from the tire tread before spin balancing. Failure to fol-
low this warning may result in injury.

NOTE: Deposits of foreign material must be cleaned from the
inside of the wheel and the tire tread to obtain a good balance.
The tire should be inspected for obvious damage, then bal-
anced according to the equipment manufacturers recommenda-
tions.

Mount wheel and tire assembly, curb side out, on dynamic
balancer and start balance cycle (Figure 6-30).

Figure 6-30: Dynamic Balancer Mounting

STEERING WHEEL NIBBLE

ADD BALANCE

WEIGHTS HERE

HEAVY SPOT

STEERING WHEEL NIBBLE

ADD BALANCE

HEAVY SPOT

WEIGHTS HERE

CURB SIDE

WHEEL AND

TIRE ASSEMBLY

DYNAMIC BALANCER

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