Hummer H1 (2006+). Manual - part 221

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Wheels and Tires/Central Tire Inflation System (CTIS)

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WHEEL ALIGNMENT CORRECTION

Alignment adjustments should be performed one at a time and in sequence to avoid errors. Recommended adjustment sequence is:

a.

caster

b.

camber

c.

front toe setting

d.

rear toe setting

e.

steering stops

Leave the vehicle on the alignment rack for each of the adjustment procedures. This way, the angle correction can be monitored
continuously during the actual adjustment.

Caster Adjustment

Caster adjustment applies to the front wheels only. It is controlled by turning the pivot bolts and the eccentric washers on the upper
control arm brackets (Figure  6-41). A positive caster angle is required on all HUMMER H1 vehicles. 

Preferred caster angle is +2.5 to +3.5 degrees. Maximum allowable side-to-side variation is 0.5 degree.

1.

Support the vehicle weight with the tires on the turntables. 

2.

Loosen the upper control arm pivot bolt locknuts by holding the bolt head and turning the locknut to allow movement of the
bolts (Figure  6-41).

3.

Pry the upper control arm brackets open to allow freedom of movement of the control arm bushings. The edges of the control
arm bushings are serrated and will be difficult to move if the brackets are not pried open.

4.

Adjust caster angle by turning the eccentrics on the upper control arm brackets in opposite directions (Figure  6-41).

• Preferred caster is +2.5 to +3.5 degrees and left-right variation must not exceed 0.5 degree.

• Turning the front eccentric outward and the rear eccentric inward increases positive caster while turning the front eccentric 

inward and the rear outward decreases it.

• Shims are available in 0.060 inch and 0.120 inch (1.5 and 3.0 mm) thicknesses for use behind the control arm mount brack-

ets if the proper angles cannot be achieved with the use of the eccentrics alone. This would be an unusual situation and the 
vehicle should be inspected thoroughly for bent or worn parts before installing shims. 

NOTE: Refer to cam alignment nut torque adapter for proper use of tool J-45764-2. 

5.

Tighten the control arm pivot bolt nuts to 260 lb-ft. (359 N•m) using torque adapter J-45764-2.

6.

Verify the correct caster angle at both front wheels. Be sure side-to-side caster variation does not exceed 0.5 degree. 

7.

 Leave the vehicle on the rack for camber and toe adjustments.

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Figure 6-41:   Caster/Camber Adjustment 

ECCENTRIC

UPPER

CONTROL

ARM

PIVOT

BOLT

PIVOT

BOLT

NUT

BUSHING

FLAT

WASHER

UPPER CONTROL

ARM BRACKET

ECCENTRIC

REFERENCE

HOLE

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Wheels and Tires/Central Tire Inflation System (CTIS)

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Camber Adjustment (Front Wheels)

Camber adjustment for the front wheels is controlled by turning the pivot bolts and eccentric washers on the upper control arm
brackets (Figure  6-41).

Preferred camber for all HUMMER H1 vehicles is zero to +0.5 degree. Maximum allowable side-to-side variation is 0.5 degree.

1.

Support the vehicle weight with the tires on the turntables and leave the hood closed.

2.

Loosen the upper control arm pivot bolt nuts by holding the bolt head and turning the nut to allow movement of the bolts
(Figure  6-41). 

3.

Pry the upper control arm brackets open to allow freedom of movement of the control arm bushings. The edges of the control
arm bushings are serrated and will be difficult to move if the brackets are not pried open.

4.

Adjust the camber angle by rotating the front eccentric of the upper control arm bracket (Figure  6-41). 

• Rotating the front eccentrics inward decreases camber (negative direction) while rotating the front eccentrics outward in-

creases the camber (positive direction). 

• Rotating the rear eccentrics of each upper control arm inward or outward in conjunction with the front eccentrics will help 

maintain the previously set caster angle. 

NOTE: Refer to cam alignment nut torque adapter for proper use of tool J-45764-2. 

5.

Tighten the control arm pivot bolts to 260 lb-ft (359 N•m) using torque adapter J-45764-2.

6.

Verify the correct camber angle at both front wheels. Be sure side-to-side variation does not exceed 0.5 degree. 

7.

Leave the vehicle on the rack for toe settings and the steering stop adjustment.

CAM ALIGNMENT NUT TORQUE ADAPTER

1.

Determine the effective length of the torque wrench (A) by measuring the distance from the center of the square drive to the 
center of the area covered by the operator’s hand (Figure  6-42).

2.

The length of the torque adapter (B) (J–45764-2) is 4 inches.

3.

When used in the straight or180 degree position, the following formula must be used:

Specified Torque x Wrench Length (A)

Wrench Length (A) + Adapter Length (B)

Example: 260 (Specified Torque) x 18.5 (Wrench Length) ÷ by 18.5 (Wrench Length) + 4 (Adapter Length) = 213.7 lb-ft.

4.

When the adapter is used at 90 degrees to the torque wrench the specified torque will be the same as the wrench setting.

5.

Using the adapter at any other angle to the torque wrench requires the above formula with the adjusted or effective length of
the adapter (B), which will be a value between 0 and 4 inches.

Figure 6-42:   Cam Alignment Nut Torque Adapter

B

A

B = 0

03-S06-002

B

NOT

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Camber Adjustment (Rear Wheels)

Camber adjustment for the rear wheels is controlled by shims installed between each upper control arm bracket and the airlift
bracket.

Preferred camber for all HUMMER H1 vehicles is +0.25 to +0.75 degrees at the rear. Maximum allowable side-to-side variation is
0.5 degree.

1.

Support lower control arms and geared hubs with jack built into alignment rack. Or, use floor jack and jack stands if rack is not
equipped with built-in-jack.

2.

Remove front and/or rear wheels as needed.

3.

Remove upper control arm pivot bolts. Retain bolts and washers but discard nuts if they are lock-type.

4.

Loosen bolts that attach upper control arm brackets to airlift bracket and frame. Do not remove the bolts; just loosen them.

5.

Adjust camber angle by changing shim between each control arm bracket and airlift bracket (Figure  6-64). 

• Use the same thickness shims between each control arm bracket and the airlift bracket.

• A thicker shim increases positive camber by 0.6º. A thinner shim increases positive camber by 0.3º. Shims are available in 

0.060 inch and 0.120 inch (1.5 and 3.0 mm) thicknesses for adjustment purposes.

6.

Add or remove shims as needed. Then tighten the control arm and airlift bracket attaching bolts to 90 ft-lb (122 N•m) torque.

Figure 6-43:   Camber Shim Location (Left Rear Shown)

7.

Install but do not fully tighten the upper control arm pivot bolts.

8.

Install the rear wheels as needed.

9.

Remove supports and position wheels on turntables.

10. Tighten control arm pivot bolts to 260 ft-lb (352 N•m) torque.

11. Verify correct camber angle at both rear wheels. Be sure side-to-side variation does not exceed 0.5 degree.

12. Leave vehicle on rack for toe settings and steering stop adjustment.

Front Wheel Toe Adjustment 

1.

Position both front wheels on the alignment rack turntables. Set the front wheels in the straight-ahead position and center the
steering gear. 

2.

Loosen the adjusting sleeve clamps on both tie rods (Figure  6-44). 

3.

Turn the sleeves until the toe measurement is within specifications. 

4.

Tighten the adjusting sleeve clamp nuts and verify the correct toe adjustment. 

CAUTION: Be sure that the bolt and nut on the adjusting sleeve clamp nut nearest to the geared hub is facing the halfshaft. The
bolt and nut on the adjusting sleeve clamp nearest to the frame must be facing away (180 degrees) from the stabilizer bar. After ad-
justment, the lengths of both tie rod end assemblies should be the same, plus or minus 1/16 inch (1.6 mm).

   AIRLIFT
BRACKETS

CONTROL ARM

 BRACKETS

 UPPER 

CONTROL ARM

 CAMBER SHIM 

 CAMBER SHIM 

PIVOT BOLT (2)