Hummer H3. Manual — part 1464

TRANSMISSION LOCKED IN ONE GEAR

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2: This step is to ensure the use of the proper transmission fluid. A special fluid is used to
ensure proper synchronizer operation and for sufficient lubrication. Improper fluid may
cause the synchronizers to stick or the transmission components to overheat.

4: A static shift test is performed by shifting into all gears with the engine not operating. By
confirming that the transmission can be shifted into all positions, ensures that the shift lever
is not excessively worn or damaged.

6: A dynamic shift test is performed by shifting into all of the gear positions with the engine
operating. Test to ensure that the internal shift components are functioning properly.

Transmission Locked in One Gear

The mainshaft bearings

The countershaft bearings

Did you find and repair the condition?

Go to Step 10

Go to Diagnostic
Aids

10

Operate the system in order to verify the
repair.
Did you correct the condition?

System OK

Go to Step 1

Step

Action

Yes

No

DEFINITION: The transmission cannot be shifted out of a gear or the vehicle will not move
because the transmission is locked.

1

Did you review the Symptoms - Manual
Transmission and perform the necessary
inspections?

Go to Step 2

Go to Symptoms
- Manual
Transmission

2

Inspect for the correct type of transmission
fluid.
Is the correct type transmission fluid being
used?

Go to Step 4

Go to Step 3

3

Drain the transmission and fill with the
correct type of fluid. Refer to
Transmission Fluid Replacement.
Did you find and repair the condition?

Go to Step 9

Go to Step 4

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

4

1. Perform a static shift test on the

transmission.

2. Test for the shift lever moving to all

positions.

Were you able to shift into all positions?

Go to Step 6

Go to Step 5

5

1. Remove the shift control housing.

2. Inspect for worn or faulty

components. Refer to Control Lever
and/or Boot Replacement.

Did you find and repair the conditions?

Go to Step 9

Go to Step 6

6

1. Perform a dynamic shift test on the

transmission.

2. Test for being able to shift in and out

of the gear with the concern.

Were you able to shift the transmission
correctly?

Go to Step 7

Go to Step 8

7

1. Remove the transmission. Refer to

Transmission Replacement.

2. Inspect the clutch system for the

clutch not releasing properly. Refer to
Clutch System Description and
Operation .

Did you find and repair the condition?

Go to Step 9

Go to Step 8

8

1. Disassemble the transmission. Refer

to Transmission Disassemble.

2. Inspect the following transmission

internal components for wear or
damage:

The shift rail

The internal shift control lever

The synchronizer components for
being broken or faulty

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

TRANSMISSION CLUNK ON ACCELERATION OR DECELERATION

Diagnostic Aids

All manual transmissions have gear play that might cause a clunk. If the transmission is suspected
of causing the clunk, compare it with a similar vehicle. An internal clunk in the transmission is
usually caused by wear between 2 components or from improper assembly, which would also
cause other symptoms.

Test Description

The number below refers to the step number on the diagnostic table.

7: This step inspects for the transfer case causing the clunk. Shift the transfer case into
another mode. If the transmission is causing the clunk, there will not be a change in the
clunk.

Transmission Clunk on Acceleration or Deceleration

The speed gears for being seized to
the mainshaft or countershaft

Did you find and repair the conditions?

Go to Step 9

Go to Diagnostic
Aids

9

Operate the system in order to verify the
repair.
Did you correct the condition?

System OK

Go to Step 1

Step

Action

Yes

No

DEFINITION: A clunk is heard and/or felt on acceleration or deceleration.

1

Did you review the Symptoms - Manual
Transmission and perform the necessary
inspections?

Go to Step 2

Go to Symptoms
- Manual
Transmission

2

Inspect the engine mounts for being loose or
damaged. Refer to Engine Mount
Inspection .
Did you find and repair the condition?

Go to Step 10

Go to Step 3

3

Inspect the transmission mounts for being
loose or damaged. Refer to Transmission
Mount Replacement.
Did you find and repair the condition?

Go to Step 10

Go to Step 4

Inspect the transmission to engine fasteners

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

TRANSMISSION FLUID LEAK DIAGNOSIS

Diagnostic Aids

Using the incorrect type of transmission fluid may affect the sealing ability of the seals. Ensure the

4

for being loose or missing. Refer to
Fastener Tightening Specifications.
Did you find and repair the condition?

Go to Step 10

Go to Step 5

5

Inspect the driveline for causing the clunk.
Refer to Diagnostic Starting Point -
Propeller Shaft .
Did you find and repair the condition?

Go to Step 10

Go to Step 6

6

Is the vehicle equipped with a transfer case?

Go to Step 7

Go to Step 9

7

Shift the transfer case into 4HI.
Is the clunk still present?

Go to Step 9

Go to Step 8

8

Inspect the transfer case for causing the
clunk. Refer to Symptoms - Transfer
Case .
Did you find and repair the condition?

Go to Step 10

Go to Step 9

9

1. Remove the transmission. Refer to

Transmission Replacement.

2. Disassemble the transmission. Refer to

Transmission Disassemble.

3. Inspect the following transmission

components that could be causing the
clunk:

Worn speed gear teeth

Worn countershaft gear teeth

Worn synchronizer sleeve to hub

Worn thrust washers and thrust
surfaces on the speed gears or
mainshaft

Did you find and repair the condition?

Go to Step 10

Go to Diagnostic
Aids

10

Operate the system in order to verify the
repair.
Did you correct the condition?

System OK

Go to Step 1

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3