GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Transmission 🢒 Manual Transmission - Tremec 5-Speed (TZ0) 🢒 Transmission Does Not Shift into One Gear

Diagnostic Aids

When the manual transmission will not transmit power from the engine to the wheels and one gear will not shift, it is possible that the gear is stripped. You should also perform a static shift and dynamic shift test. If the transmission will not shift in all gears, it is possible the input or countershaft gears are stripped or there is a broken input or output shaft. Sometimes the transmission shift control may not be operating properly.

Test Description

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

  1. This step inspects for worn or damaged shift control components.

    2.

  2. This step inspects for any conditions with the hydraulic system.

    3.

  3. This step inspects for worn or damaged internal components.

Step

Action

Yes

No

DEFINITION: The transmission does not shift into a gear.

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 transmission shift lever operation.

Is the control worn, binding, or damaged?

Go to Step 3

Go to Step 3

3

Replace the transmission shift lever. Refer to Transmission Control Lever Knob Replacement and Transmission Control Lever Boot Replacement .

Did you find and repair the condition?

System OK

Go to Step 4

4

Inspect the hydraulic clutch operation. Refer to Symptoms - Clutch .

Is the clutch operating properly?

Go to Step 6

Go to Step 5

5

Replace the concentric slave cylinder. Refer to Clutch Actuator Cylinder Replacement .

Did you find and repair the condition?

System OK

Go to Step 6

6

  1. Remove the transmission. Refer to Transmission Replacement .
  2. Inspect the transmission input shaft and the clutch pilot bearing.

Is there signs of the input shaft binding in the pilot bearing?

Go to Step 7

Go to Step 8

7
  1. Inspect the clutch pilot bearing for damage.
  2. Replace the clutch pilot bearing. Refer to Clutch Pilot Bearing Replacement .

Did you find and repair the condition?

System OK

Go to Step 8

8

Disassemble and inspect the following transmission internal components for wear or damage:

    • Gearshift components
    • Transmission gears
    • Bearings

Did you find any worn or damaged components?

Go to Step 9

System OK

9
  1. Replace worn or damaged components, as necessary.
  2. Install the transmission. Refer to Transmission Replacement .

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