Primary Procedure

DESCRIPTION
Vibration or shudder which is noticeable either on fast acceleration, when coasting or when using the engine for braking may be caused by the rear axle housing being loose on the rear suspension, improper tire balance, improper driveline installation or balance.

If driveshaft components are replaced and shaft vibration is encountered after installation, disconnect the driveshaft and remove the driveshaft slip yoke. Rotate the driveshaft slip yoke 180°. Then reconnect the driveshaft to the driveshaft slip yoke and reinstall in vehicle. If the vibration persists, disconnect the driveshaft at the rear axle universal joint flange. Rotate the flange 180° and reconnect the driveshaft to the rear axle universal joint flange. If rotating the driveshaft 180° does not eliminate vibration, the shaft may be balanced using the following procedure.

PROCEDURE
1. Raise the vehicle on a hoist so rear axle is safely supported with wheels free to rotate at normal ride height.
2. With the transmission in gear, increase the vehicle speed to maximum vibration level. Note and record the speed of this vibration period as a baseline speed.





3. With the transmission in gear, run the vehicle with the driveshaft rotating at a speed of 64-80 km/h (40-50 mph). Have an assistant carefully bring a crayon, piece of chalk or colored pencil up until it just barely contacts the rear end, center and front end of the driveshaft. The chalk marks will indicate the heavy side of the shaft.

WARNING: USE CAUTION WHEN CHECKING THE DRIVESHAFT NEAR THE BALANCE WEIGHTS TO PREVENT INJURY TO THE HANDS.





4. Install two screw-type hose clamps on the driveshaft so their heads are located 180° from the chalk mark, starting at the rear axle universal joint flange end of the driveshaft. Tighten the clamps.
5. Accelerate the vehicle up to the baseline speed. If vibration is still evident, rotate the clamps approximately 45° away from each other and test for correction of vibration.

CAUTION: Do not run the engine on the hoist with the transmission engaged for extended periods due to the danger of overheating the engine or transmission.

6. If necessary, continue to rotate the clamps apart in smaller increments until the vibration becomes reduced or eliminated.
7. If the vibration is not completely eliminated, repeat the above procedure and balance the front end of the driveshaft, checking for elimination or reduction of the vibration.





8. Remove the vehicle from the hoist and perform a road test.