Hummer H2. Manual - part 2398

Engine mounts - Vibration of the mounts can be multiplied by TCC engagement.

Axle joints - Check for vibration.

TP Sensor - The TCC apply and release depends on the TP Sensor in many engines. If the TP Sensor is
out of specification, TCC may remain applied during initial engine loading.

Cylinder balance - Bad piston rings or poorly sealing valves can cause low power in a cylinder.

Fuel contamination - This causes poor engine performance.

Replace the torque converter if any of the following conditions exist:

External leaks appear in the hub weld area.

The converter hub is scored or damaged.

The converter pilot is broken, damaged, or fits poorly into the crankshaft.

You discover steel particles after flushing the cooler and the cooler lines.

The pump is damaged, or you discover steel particles in the converter.

The vehicle has TCC shudder and/or no TCC apply. Replace the torque converter only after all hydraulic
and electrical diagnoses have been made. The converter clutch material may be glazed.

The converter has an imbalance which cannot be corrected. Refer to Flexplate/Torque Converter
Vibration Test .

The converter is contaminated with engine coolant which contains antifreeze or water.

An internal failure occurs in the stator roller clutch.

You notice excessive end play.

Overheating produces heavy debris in the clutch or converter ballooning.

You discover steel particles or clutch lining material in the fluid filter or on the magnet, when no internal
parts in the unit are worn or damaged. This condition indicates that lining material came from the
converter.

Do not replace the torque converter if you discover any of the following symptoms:

The oil has an odor or the oil is discolored, even though metal or clutch facing particles are not present.

The threads in one or more of the converter bolt holds are damaged. Correct the condition with a new
thread inset.

Transmission failure did not display evidence of damaged or worn internal parts, steel particles or clutch
plate lining material in the unit and inside the fluid filter.

The vehicle has been exposed to high mileage only. An exception may exist where the lining of the
torque converter clutch dampener plate has seen excess wear by vehicles operated in heavy and/or
constant traffic, such as taxi, delivery, or police use.

FLEXPLATE/TORQUE CONVERTER VIBRATION TEST

Isolating Vibration

NOTE:

Some engine/transaxle combinations cannot be balanced in this manner due to

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

To isolate and correct a flywheel or torque converter vibration, separate the torque converter from the flywheel
to determine if vibration is in the engine or transmission.

1. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.

2. Turn the engine OFF.

3. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

4. Remove the transmission converter cover bolts and the cover.

5. Mark the relationship of the converter to the flywheel.

6. Remove the bolts attaching the converter to the flywheel.

7. Slide the torque converter away from the flywheel.

8. Rotate the flywheel and torque converter to inspect for defects or missing balance weights. Refer to

Engine Flywheel Cleaning and Inspection in Engine Mechanical - 6.0L (LQ4).

9. Lower the vehicle.

10. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. Refer

to Diagnostic Starting Point - Vibration Diagnosis and Correction in Vibration Diagnosis and
Correction.

11. Turn the engine OFF.

Indexing Torque Converter

To determine and correct a torque converter vibration, the following procedure may have to be performed
several times to achieve the best possible torque converter to flywheel balance.

1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

2. Rotate the torque converter one bolt position.

restricted access or limited clearances between the torque converter bolts and
the engine. Ensure that the bolts do not bottom out in the lug nuts or the torque
converter cover could be dented and cause internal damage.

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

Fig. 4: Aligning Torque Converter Hub In Engine Crankshaft
Courtesy of GENERAL MOTORS CORP.

3. Align the torque converter hub (2) in the engine crankshaft (3) and install the torque converter to flywheel

bolts.

4. Lower the vehicle.

5. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. Refer

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

to Noise and Vibration Analysis .

Repeat this procedure until you obtain the best possible balance.

6. Install the transmission converter cover bolts and the cover.

NOISE AND VIBRATION ANALYSIS

A noise or vibration that is noticeable when the vehicle is in motion MAY NOT be the result of the
transmission.

If noise or vibration is noticeable in PARK and NEUTRAL with the engine at idle, but is less noticeable as
RPM increases, the cause may be from poor engine performance.

Vibration may also be caused by a small amount of water inside the converter.

Inspect the tires for the following conditions:

{

Uneven wear

{

Imbalance

{

Mixed sizes

{

Mixed radial and bias ply

Inspect the suspension components for the following conditions:

{

Alignment and wear

{

Loose fasteners

{

Driveline damage or wear

Inspect the engine and transmission mounts for damage and loose bolts.

Inspect the transmission case mounting holes for the following conditions:

{

Missing bolts, nuts, and studs

{

Stripped threads

{

Cracks

Inspect the flywheel for the following conditions:

{

Missing or loose bolts

{

Cracks

{

Imbalance

Inspect the torque converter for the following conditions:

{

Missing or loose bolts or lugs

{

Missing or loose balance weights

{

Imbalance caused by heat distortion or fluid contamination

CLUTCH PLATE DIAGNOSIS

Composition Plates

2004 Hummer H2

2004 TRANSMISSION Automatic Transaxle - 4L60-E/4L65-E (Troubleshooting)

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