GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 Transmission Noisy

Diagnostic Aids

The manual transmission can be noisy for a number of reasons, from being noisy in neutral, low, high and reverse gear. Diagnosis the transmission for the level of fluid to the right type of fluid in the transmission. If the transmission is in neutral and engaged and makes a whirling kind of a noise and is heard outside the vehicle, this is a normal conditions for this type of manual transmission.

Test Description

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

  1. This step is checking for the correct fluid level.

    2.

  2. This step is checking for the correct type of transmission fluid.

    3.

  3. This step is checking for internal damage or worn parts.

Step

Action

Yes

No

DEFINITION: The transmission is noisy and the noise carries into the passenger compartment.

1

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

Go to Step 2

Go to Symptoms - Manual Transmission

2

Inspect the transmission fluid level.

Is the fluid level correct?

Go to Step 4

Go to Step 3

3

Add transmission fluid. Refer to Fluid Replacement .

Did you find and repair the condition?

System OK

Go to Step 4

4

Inspect the transmission for the correct fluid type. Refer to Lubrication Specifications .

Is the transmission fluid the correct type?

Go to Step 6

Go to Step 5

5

Drain and refill the transmission with the correct type fluid. Refer to Fluid Replacement .

Did you find and repair the condition?

Go to Step 12

Go to Step 6

6

Inspect the shift tower boot.

Is the closeout boot loose or damaged?

Go to Step 7

Go to Step 8

7

Position and tighten the shift tower to specification, or replace the boot as necessary. Refer to Shift Tower Replacement .

Did you find and repair the condition?

Go to Step 12

Go to Step 8

8

Inspect the clutch housing for loose bolts and/or misalignment with the engine.

Is there any loose bolts or misalignment with the engine?

Go to Step 9

Go to Step 10

9

Tighten the clutch housing bolts to specifications. Refer to Fastener Tightening Specifications in Clutch.

Did you find and repair the condition?

System OK

Go to Step 10

10

  1. Remove the transmission. Refer to Transmission Replacement .
  2. Disassemble the transmission. Refer to Transmission Disassemble . Inspect the following transmission components for wear or damage:
    3. • Gear shift components
    • Transmission gears
    • Bearings

Is there any wear or damage?

Go to Step 11

System OK

11
  1. Replace worn or damaged components as necessary.
  2. Install the transmission. Refer to Transmission Replacement (ZF S6-650).

Did you find and repair the condition?

Go to Step 12

Go to Diagnostic Aids

12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1