Hummer H1 (2006+). Manual — part 219

6-26

Wheels and Tires/Central Tire Inflation System (CTIS)

_______________

Figure 6-31: Balance Weight Placement

TROUBLESHOOTING A NON-BALANCING WHEEL AND TIRE ASSEMBLY

NOTE: If a wheel and tire assembly cannot be balanced, or balance cannot be maintained, any of the following conditions may be
causing the problem:

• The run flat is moving on the wheel/rim.

• Excessive radial or lateral run out condition of the wheel.

• Improper seating of the tire bead on the wheel flange.

NOTE: Perform the following if the run flat is moving on the wheel. If an excessive run out condition is suspected, proceed to
Wheel End Vibration Correction Using Road Force Values.

Suspected Run Flat Movement Procedure

1.

Disassemble the wheel and remove the run flat from the tire.

2.

Clean the inside of the tire, wheel and the O-ring seal with soap and water. Allow the cleaned parts to dry prior to assembly.

3.

Apply run flat gel lubricant at the crown area on the inside tire area.

4.

Install the run flat into the tire and assemble the wheel.

5.

Balance the wheel and tire assembly.

WHEEL END VIBRATION CORRECTION USING ROAD FORCE VALUES

Initial Checks

NOTE: Before performing any vibration analysis or balance operations, drive the vehicle to warm the tires.

1.

Verify the customer complaint at the affected speed, with tire pressures set to 26 psi. front and 28 psi. rear. Many tire vibrations
will not be evident until the vehicle is driven long enough for the tires to reach operating temperature (10 minutes at highway
speed).

2.

After the complaint is verified, check all wheel end parts that could contribute to a vibration, i.e.: loose lug nuts, spindle
bearings, tie rod ends, idler arm, pitman arm, steering gear and idler arm mount bolts. Perform a visual inspection of the
wheels and tires for physical damage.

WHEEL

WHEEL AND

TIRE ASSEMBLY

WEIGHT

(TAPE-ON TYPE)

ASSEMBLY

LIGHT SPOT

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Wheels and Tires/Central Tire Inflation System (CTIS) 6-27

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PROCEDURE

NOTE: Before proceeding with the following procedures, authorization from the AM General Warranty Department must be ob-
tained.

Assembly Road Force Check Procedure

NOTE: The following tire and wheel checks must be performed on a Hunter GSP 9700 Road Force

TM

measurement balance ma-

chine. If the machine is not available at your location, visit the Hunter website (www.gsp9700.com/pub/search/findgsp9700.cfm)
to find a machine at a nearby location.

NOTE: Before mounting the wheel/tire assemblies on the balance machine, drive the vehicle to warm the tires and raise the tires
off the ground to eliminate flat spotting.

NOTE: Use the following Hunter GSP 9700 wheel mount equipment:

• 3 inch diameter by 5/8 inch thick plastic spacer

• centering cone number 173 (purple color code) large diameter side towards the wheel

• flange plate with four rounded end pins

• wing nut with pressure ring

NOTE: If the high tire runout and the low wheel runout points are between 90 and 180 degrees apart, the tire can be rotated on the
wheel to obtain more favorable road force values.

1.

Set all tire pressures to 28 psi. and perform the road force variation and balance procedures. Mark the high runout spot of the
tire and the low runout spot of the wheel as indicated. If the assembly TIR (total indicated reading) road force exceeds 55 lb.,
or the assembly R1H (radial first harmonic) road force exceeds 35 lb., at 28 psi., rotate or replace the tire. Replacement tires
must be obtained from the AM General Service Parts Logistics Operation.

2.

Repeat the tire/wheel check procedure for the remaining assemblies.

Geared Hub Spindle Check Procedure

Measure the spindle stud radial runout and the spindle face lateral runout with dial indicator J–8001 and roller adapter J–23672.

NOTE: Mount the dial indicator base to the geared hub housing to get reliable readings.

1.

Position the dial indicator to measure the wheel mount stud radial runout at 1/2 inch out from the face of the spindle
(Figures 6-32 and 6-33). The indicator shaft must be positioned inline with an imaginary line starting at one stud, running
across the face of the spindle through the opposing stud and the indicator.

2.

Rotate the spindle slowly (by hand) past each stud and record the difference between the lowest reading stud and the highest
reading stud. The maximum allowable difference is 0.020 inch. If the reading is within the specification, mark the stud with
the lowest reading and move on to the next step. If the reading is larger than the specification, replace the geared hub spindle.

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6-28

Wheels and Tires/Central Tire Inflation System (CTIS)

_______________

Figure 6-32: Wheel Mount Stud Radial Runout

Figure 6-33: Indicator Position For Radial Runout Test

NOTE: Ensure that the spindle machined face is clean and free of rust, paint, etc. before attempting to perform the spindle lateral
runout test.

3.

Position the dial indicator to measure the geared hub spindle lateral runout (See Figures 6-34 & 6-35). The indicator wheel
should be positioned outboard of the stud circle perpendicular to the face of the spindle. The indicator wheel will have to be
lifted off the face when rotating the spindle cutout areas past the indicator. The best indicator mount position is on the geared
hub housing with a magnetic base.

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Wheels and Tires/Central Tire Inflation System (CTIS) 6-29

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Figure 6-34: Geared Hub Spindle Lateral Runout Test

Figure 6-35: Indicator Position For Lateral Runout Test

4.

Rotate the spindle slowly (by hand) and record the difference between the lowest and the highest reading on the indicator. The
maximum difference should be 0.005 inch. If the reading is within the specification, move on to the next step. If the reading is
larger than the specification, replace the geared hub spindle.

5.

Repeat the spindle checks for the remaining spindles and install the tire/wheel assemblies.

6.

Duplicate the complaint drive conditions and verify the repair.

WHEEL ALIGNMENT

Check the alignment on a alignment rack with the front tires in the straight-ahead position and inflated to the manufacturer’s rec-
ommended pressure.

Preliminary Inspection

1.

Check the tire condition, tread wear (Figure 6-26), run-out, and inflation.

2.

Raise and support the vehicle so the wheels are free to rotate. Then secure the steering wheel in the straight-ahead position.

3.

Check the tie rods and the upper control arms for distortion, play, or looseness (Figure 6-36). Replace any worn, or damaged
parts before proceeding.

MACHINED

FACE

CUTOUT

AREA

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