Balancing, Driveshaft

The first check to be performed when driveshaft vibration is suspected is re-indexing the driveshaft at both the rear axle and transmission.

A vibration-free driveline can result from the driveshaft indexing procedure when minor driveshaft imbalance is cancelled by minor system runouts.
1. Raise vehicle on hoist. Remove rear wheel and tire assemblies and rear drum or rotor assemblies. Place floor stands under suspension arms to support rear of vehicle. Note or mark indexing of driveshaft to transmission and rear axle universal joint flange.
2. Mark one hole position on axle flange at rear of driveshaft with the letter A and the eight rear axle U-joint flange holes (starting with the mating hole with driveshaft position A) from one through eight. Position A-1 is considered the original index position.

NOTE: Check rear axle shaft universal joints for binding during first re-indexing.

3. Disconnect driveshaft, re-index 180 degrees at axle position A-5. Check for vibration at road test speed. If vibration is still present, evaluate positions A3 and A7.
4. If further improvement is desired, evaluate remaining positions that are located between the best of the two previous positions, A-3 and A-7. If vehicle tests satisfactorily at any point during this procedure, do not proceed with any further steps.
5. If re-indexing at axle is unsuccessful, disconnect the driveshaft, re-index 180 degrees at transmission only and connect. Check for vibration at road test speed. If vehicle tests satisfactorily, do not proceed with any further steps.

NOTE: Remove driveshaft from vehicle and manipulate rear axle shaft universal joints in each direction of rotation. If a rear axle shaft universal joint feels stiff or has a lumpy, gritty feel in any direction, replace rear axle shaft universal joints.

6. If re-indexing at both axle and transmission is unsuccessful.

NOTE: Original equipment driveshaft-to-axle companion flange retaining bolts (N-800594-S100) are Loctite(R) coated and do not require a lockwasher. If these bolts are removed, apply additional Loctite(R) prior to installation. New and used bolts must be tightened to 95-129 N.m (70-95 lb-ft). ,