Vibration at 45-65 MPH

Vibration at 45-65 mph transmitted to the seats, floor and/or steering column may be caused by an out-of-balance driveshaft. This condition may be corrected as follows:
1. Raise vehicle on a hoist.
2. Ensure paint marks on driveshaft and axle end yoke are properly matched. Realign if necessary. If vibration still exists, proceed to step 3.
3. Remove rear halfshaft assemblies from vehicle, then road test vehicle with AWD switch in the Off position. The AWD feature must not be engaged while operating vehicle with the halfshafts removed while the vehicle is moving.
4. If vibration is still present, balance the wheel and tire assemblies.
5. Install rear halfshaft assemblies.
6. With the vehicle at a complete stop, depress the AWD switch to the On position, then allow vehicle to roll forward for approximately 30 feet until the AWD system engages.
7. Road test vehicle and check for vibration. If vibration still exists, balance the driveshaft as follows:
a. Remove wheel and tire assemblies, then reinstall all lug nuts. Do not allow suspension to hang freely. If the CV joint is run at a very high angle, damage to the seals and joints may occur. Also, support lower control arm out as far as possible. To bring vehicle to proper ride height, the full weight of the vehicle should be supported by front floor jacks.
b. Mark rear of driveshaft in four equal parts, numbering them 1 through 4.
c. Install a Whittek type hose clamp at rear of driveshaft assembly forward of the torque tube at position No. 1, then operate driveline at speed which vibration occurred.
d. Rotate clamp to each of the other three positions and check for vibrations.
e. If vibration is worse in all positions, proceed to step 10. If vibration is less in any one position, proceed to step 8. If vibration is less in any two position, rotate clamp screw to a mid-point between the two positions, then proceed to step 8.
f. Install another clamp with screw in same position as first clamp, then operate vehicle at speed which vibration occurred. If vibration is not corrected, proceed to step 9.
g. Rotate screws of clamps equally away from each other approximately 1/2 inch, then operate driveline at speed which vibration occurred.
h. If vibration is corrected with both clamps installed, they should remain on the driveshaft assembly. If vibration is less with one clamp than with two clamps, remove one clamp and return remaining clamp to best position previously set.