GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Tracker - 4WD 🢒 General Information 🢒 Vibration Diagnosis and Correction 🢒 Vibration Analysis - Driveline

Test Description

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

  1. In most cases, the vibration can be reproduced in the stall, but it is either not as bad or a lot worse than experienced on the road. This is normal. The cause of first-order driveline vibrations is usually due to excessive runout or the imbalance of a component. The In-Stall test will help determine which component needs to be repaired or replaced.

    2.

  2. First-order driveline vibrations can be caused by excessive runout of the propeller shaft.

  3. First -order driveline vibrations can be caused by excessive runout of the pinion flange. If a propeller shaft has excessive runout at the pinion flange only, and re-indexing the propeller shaft 180 degrees does not correct the condition, measure and correct the pinion flange runout before replacing the propeller shaft.

    4.

  4. Re-indexing the propeller shaft to the pinion flange aligns the runout of components which may reduce vibration. If vibration is not reduced or eliminated, return the components to their original positions.

Step

Action

Yes

No

1

Has the Vibration Analysis - Road Testing Table been completed?

Go to Step 2

Go to Vibration Analysis - Road Testing

2

Did you record frequency data from the J 38792-A during the Vibration Analysis - Road Testing procedure?

Go to Step 3

Go to Step 5

3

Based on the Vibration Analysis - Road Testing Table, is the concern first order driveline related?

Go to Step 6

Go to Step 4

4

Based on the Vibration Analysis - Road Testing Table, is the concern second order driveline related?

Go to Step 18

Go to Step 5

5

Based on the Vibration Analysis - Road Testing Table, is the concern a noise that is not felt?

Go to Vibration Diagnostic Aids

Go to Vibration Analysis - Road Testing

6

Inspect the following components for wear or damage:

    • Inspect the propeller shafts for dents, damage, missing weights, and undercoating.
    • Inspect the U-joints for damage and missing components.
    • Inspect the center bearings (if applicable) for damaged rubber components, worn bearings, or a cracked bracket.

Are any of the components listed worn or damaged?

Go to Step 7

Go to Step 8

7

Replace the damaged or missing components. Refer to one of the following procedures in Propeller Shaft:

Did you complete the replacement?

Go to Step 25

--

8

Attempt to duplicate the vibration in the stall. Refer to Vibration in Service-Stall Test (Non-Torque Sensitive) .

Were you able to duplicate the vibration?

Go to Step 9

Go to Step 10

9

Was the vibration most evident under the transmission mount?

Go to Step 10

Go to Step 12

10

Measure the runout at the rear of the front axle propeller shaft, if equipped and measure the runout at the front of the rear axle propeller shaft. Refer to Propeller Shaft Runout Measurement .

Does the runout measurement require that the propeller shaft be replaced?

Go to Step 12

Go to Step 11

11
  1. Replace the transmission or transfer case mount. Refer to the appropriate procedure, following:
    2. •  Rear Transmission Mount in Manual Transmission - M59
    •  Transfer Case Mount Replacement in Transfer Case - Tracker
  2. Perform the Vibration in Service-Stall Test (Non-Torque Sensitive) .

Is the vibration still present?

Go to Step 12

Go to Step 25

12

Measure the runout of the complete propeller shaft. Refer to Propeller Shaft Runout Measurement .

Does the runout measurement require that the propeller shaft be replaced?

Go to Step 13

Go to Step 14

13
  1. Replace the propeller shaft. Refer to appropriate procedure in Propeller Shaft:
  2. Perform the Vibration in Service-Stall Test (Non-Torque Sensitive) .

Was the vibration reduced or eliminated?

Go to Step 25

Go to Step 16

14

Determine the runout of the front axle pinion flange, if equipped and determine the runout of the rear axle pinion flange. Refer to the Pinion Flange Runout Measurement .

Does the runout measurement require that the pinion flange be replaced?

Go to Step 15

Go to Step 16

15

Replace the pinion flange. Refer to Drive Pinion Flange/Yoke and/or Oil Seal Replacement in Rear Drive Axle.

Did you complete the replacement?

Go to Step 25

--

16

Re-index the propeller shaft. Perform the following steps:

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Mark the position of the shaft on the pinion flange.
  3. Remove the propeller shaft from the pinion flange.
  4. Rotate the propeller shaft 180 degrees in the pinion flange.
  5. Reinstall the propeller shaft.
  6. Attempt to duplicate the vibration in the stall. Refer to the Vibration in Service-Stall Test (Non-Torque Sensitive) .

Was the vibration reduced or eliminated?

Go to Step 25

Go to Step 17

17

Return the propeller shaft to its original position and balance the propeller shaft. Refer to Driveline System Balance Adjustment .

Were you able to balance the driveline system?

Go to Step 25

Go to Vibration Diagnostic Aids

18

Inspect the following components for wear or damage:

    • Inspect the propeller shafts for dents, damage, missing weights, and undercoating.
    • Inspect the U-joints for damage and missing components.
    • Inspect the center bearings, if applicable, for damaged rubber components, worn bearings, or a cracked bracket.

Are any of the components listed worn or damaged?

Go to Step 19

Go to Step 20

19

Replace the damaged or missing components. Refer to one of the following procedures in Propeller Shaft:

Did you complete the replacement?

Go to Step 25

--

20
  1. Measure the vehicle trim height.
  2. Adjust the vehicle trim height, if necessary.

Refer to Trim Height Inspection in Suspension General Diagnosis.

Did you find and correct a condition?

Go to Step 25

Go to Step 21

21

Measure the propeller shaft angles. Refer to Driveline Working Angles Measurement .

Do the propeller shaft angles require adjustment?

Go to Step 22

Go to Step 23

22

Adjust the propeller shaft angles.

Did you complete the repair?

Go to Step 25

--

23

Inspect the propeller shafts for proper phasing. Refer to Propeller Shaft Phasing Inspection .

Does the propeller shaft phasing require correction?

Go to Step 24

Go to Vibration Diagnostic Aids

24

Correct the propeller shaft phasing. Refer to Propeller Shaft Phasing Correction .

Did you complete the repair?

Go to Step 25

--

25
  1. Install or connect any components that were removed or disconnected during diagnosis.
  2. Perform the Vibration Analysis - Road Testing Table. Refer to Vibration Analysis - Road Testing .

Is the vibration still present?

Go to Step 3

System OK