Out-of-round tires or wheels that are out of balance, will cause a low frequency vibration.
Driveline vibration can also be caused by loose or damaged engine mounts.
Propeller shaft vibration increases with vehicle speed. A vibration that occurs at a specific speed range, is not usually caused by an out of balance propeller shaft. Defective universal joints or an incorrect propeller shaft angle are usually the cause of such a vibration.
| CONDITION | POSSIBLE CAUSE | CORRECTION |
|---|---|---|
| Propeller Shaft Noise | 1) Undercoating or other foreign material on shaft. | 1) Clean exterior of shaft and wash with solvent. |
| 2) Loose companion flange bolts. | 2) Install new bolts and tighten to proper torque. | |
| 3) Loose or bent U-joint yoke or excessive runout. | 3) Install new yoke. | |
| 4) Incorrect driveline angularity. | 4) Measure and correct driveline angles. | |
| 5) Rear spring center bolt not in seat. | 5) Loosen spring U-bolts and seat center bolt. | |
| 6) Worn U-joint bearings. | 6) Install new U-joint. | |
| 7) Propeller shaft damaged or out of balance. | 7) Install new propeller shaft. | |
| 8) Broken rear spring. | 8) Install new rear spring. | |
| 9) Excessive runout or unbalanced condition. | 9) Re-index propeller shaft, test, and evaluate. | |
| 10) Excessive drive pinion gear shaft runout. | 10) Re-index propeller shaft and evaluate. | |
| 11) Excessive axle yoke deflection. | 11) Inspect and replace yoke if necessary. | |
| 12) Excessive transfer case runout. | 12) Inspect and repair as necessary. | |
| Universal Joint Noise | 1) Loose companion flange bolts. | 1) Install new bolts and tighten to proper torque. |
| 2) Lack of lubrication. | 2) Replace U-joints as necessary. |
DRIVELINE VIBRATION
Scheme 1
If propeller shaft is suspected of being out of balance, use the following procedure.
Note. Indexing propeller shaft 180 degrees relative to the yoke may eliminate some vibrations.
Scheme 2
Scheme 3
- Raise and support vehicle.
- Clean all foreign material from the propeller shaft and universal joints.
- Inspect propeller shaft for missing balance weights, broken welds and bent areas. If propeller shaft is bent, it must be replaced.
- Inspect universal joints for wear and properly installed.
- Check propeller shaft bolt torques.
- Remove wheels and install lug nuts to retain brake rotors.
- Mark and number the shaft six inches from the pinion yoke end at four positions 90 degrees apart.
- Run and accelerate vehicle until vibration occurs. Note the intensity and speed the vibration occurred. Stop the engine.
- Install a screw clamp at position (1).
- Start engine and check vibration. If there is little or no change move the clamp to the next positions. Repeat the vibration test. NOTE: If there is no difference in vibration at this positions, the vibration may not be the propeller shaft.
- If vibration decreased, install a second clamp (1) and repeat the test.
- If additional clamp causes an additional vibration, separate the clamps 1/2 inch (1) above and below the mark. Repeat the vibration test.
- Increase distance between the clamp screws (1) (2) and repeat test, until the least amount of vibration is noticed. Bend the slack end of the clamps so screws will not loosen.
- If vibration remains unacceptable, repeat the procedure to the front end of the propeller shaft.
- Install wheels and lower vehicle.
Scheme 4
This procedure applies to front and rear propeller shafts.
Note. To obtain output angle (A) on the front propeller shaft equipped with a C/V joint, place inclinometer on machined surface of the C/V joint.
Scheme 5
Scheme 6
- Raise vehicle and support the axles as level as possible, allowing the wheels and propeller shaft to turn.
- Remove universal joint snap rings if equipped, so inclinometer base sits flat.
- Rotate shaft until transmission/transfer case output yoke bearing is facing downward. NOTE: Always take measurements from front to rear and on the same side of the vehicle.
- Place Inclinometer (special tool #7663, Inclinometer) on yoke bearing cap or pinion flange ring parallel to the shaft. Center bubble in sight glass and record measurement (A). This measurement will give you the transmission yoke Output Angle (A).
- Rotate propeller shaft 90 degrees and place Inclinometer on yoke bearing parallel to the shaft. Center bubble in sight glass and record measurement. This measurement can also be taken at the rear end of the shaft. This measurement will give you the Propeller Shaft Angle (C).
- Rotate propeller shaft 90 degrees and place inclinometer on companion flange yoke bearing parallel to the shaft. Center bubble in sight glass and record measurement. This measurement will give you the pinion Companion Flange Input Angle (B).
- Subtract smaller figure from larger (C minus A) to obtain Transmission/Transfer Case Output Operating Angle .
- Subtract smaller figure from larger (C minus B) to obtain axle Input Operating Angle .
Scheme 7
Refer to rules and example below for additional information.
RULES
- Good cancellation of U-joint operating angles should be within 1 degree.
- Operating angles should be less than 3 degrees.
- Operating angles less than 10 degrees for double cardan U-joint.
- At least 1/2 of one degree continuous operating propeller shaft angle.
Scheme 8
Two piece propeller shaft angles measurement is the same as a one-piece propeller shaft.
Scheme 9
Vehicles with double cardan universal joint front propeller shaft (1) are equipped with a grease fitting (2). Grease the double cardan universal joint at each oil change.