GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Sonoma Pickup - 4WD 🢒 Engine 🢒 Engine Electrical 🢒 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. If the transmission will not shift in all gears it is possible that the input or countershaft gears are stripped or a broken input or output shaft has occurred. Sometimes the transmission shift control may not be working correctly. You should also perform a static shift and a dynamic shift test.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks for worn or damage shift control components.

    2.

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

    3.

  3. This step inspects for internal parts that may have worn or damaged components.

Step

Action

Yes

No

DEFINITION: The transmission does not shift into a gear.

1

Did you review the manual transmission symptom and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Manual Transmission

2

Inspect the operation of the transmission shift lever.

Is the control worn, binding, or damaged?

Go to Step 3

Go to Step 4

3

Replace the transmission shift lever. Refer to Shift Lever Replacement .

Did you find and repair the condition?

System OK

Go to Step 4

4

Inspect the hydraulic clutch operation. Refer to Symptoms - Manual Transmission in Clutch.

Is the clutch operating properly?

Go to Step 6

Go to Step 5

5

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

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. Replace the clutch pilot bearing. Refer to Clutch Pilot Bearing Replacement in Clutch.
  2. Install the transmission. Refer to Transmission 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

Are any of the components worn or damaged?

Go to Step 9

System OK

9
  1. Replace all worn or damaged components. Refer to Transmission/Transaxle/Transfer Case Unit Repair Manual.
  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