Hummer H2. Manual - part 2188

2. Check the fuel level. Add additional weight if necessary to simulate a full tank.  

3. Make sure the rear compartment is empty except for the spare tire.  

4. Make sure the vehicle is on a level surface, such as an alignment rack.  

Z Height Measurement 

1. Lift the front bumper of the vehicle up about 38 mm (1.5 in).  

2. Remove your hands.  

3. Allow the vehicle to settle into position.  

4. Repeat this jouncing operation 2 more times for a total of 3 times. 

Fig. 3: Measuring Z Dimension 
Courtesy of GENERAL MOTORS CORP. 

5. Measure from the pivot bolt center line (3) down to the lower corner (5) of the lower ball joint (1) in 

order to obtain the Z height measurement (4).  

6. Push the front bumper of the vehicle down about 38 mm (1.5 in).  

7. Remove your hands.  

8. Allow the vehicle to rise.  

9. Repeat the operation for a total of 3 times.  

10. Measure the Z dimension.  

 

2004 Hummer H2 

2004 SUSPENSION Suspension General Diagnosis - Hummer H2

  

11. The true Z height dimension number is the average of the high and the low measurements. Refer to Trim 

Height Specifications .  

Z Height Adjustment 

1. For vehicles equipped with a torsion bar suspension turn the bolt (1) that contacts the torsion arm 

clockwise to raise the and counterclockwise to lower the height adjustment. One revolution of the bolt (1) 
into the nut increases the Z height by approximately 6.0 mm (0.2 in). 

Fig. 4: Turning Bolt That Contacts Torsion Arm (Vehicles Equipped With Torsion Bar 
Suspension) 
Courtesy of GENERAL MOTORS CORP. 

2. For vehicles without torsion bars, replace damaged or worn components as necessary.  

D Height Measurement 

The D height dimension measurement determines the proper rear end ride height. There is no adjustment 
procedure. Repair may require replacement of suspension components. 

1. With the vehicle on a flat surface, lift upward on the rear bumper 38 mm (1.5 in).  

2. Remove your hands.  

3. Allow the vehicle to settle into position.  

4. Repeat the jouncing operation 2 more times for a total of 3 times. 

 

2004 Hummer H2 

2004 SUSPENSION Suspension General Diagnosis - Hummer H2

  

Fig. 5: Measuring D Height Dimension 
Courtesy of GENERAL MOTORS CORP. 

5. The D height is obtained by measuring the distance between the edge of the jounce cup along the jounce 

bumper center line and the jounce pad on the rear axle.  

6. The true D height dimension number is the average of the high and the low measurements. Refer to Trim 

Height Specifications .  

7. If these measurements are out of specifications, inspect for the following conditions: 

z

Sagging front suspension 

Refer to Torsion Bar Replacement in Front Suspension. 

z

Sagging rear coil springs 

Refer to Coil Spring Replacement in Rear Suspension. 

z

Proper air suspension operation.  

z

Worn rear suspension components.  

z

Improper tire inflation 

 

2004 Hummer H2 

2004 SUSPENSION Suspension General Diagnosis - Hummer H2

  

Refer to Tire Inflation Pressure Specifications in Maintenance and Lubrication. 

z

Improper weight distribution  

z

Collision damage  

SPECIAL TOOLS AND EQUIPMENT 

SPECIAL TOOLS 

Special Tools 

Illustration

Tool Number/Description

J 8001 

Dial Indicator

J 39570 

Chassis Ear

 

2004 Hummer H2 

2004 SUSPENSION Suspension General Diagnosis - Hummer H2