vibration when letting off the gas...

[97splorer]

When driving highway speeds (50-70mph) I noticed a strong vibration when I let off the gas. When I pushed the gas to keep speed the vibration stops. What could cause it to vibrate when coasting? I did drive thru a little mud yesterday but not enough to get packed into anything. Could this be bad u-joints? Any opinions?

Thanks-Brian

 

[james t]

Usually it means the Ujoint in the rear driveshaft is about to let go- unless you've changed something lately (more lift/etc).

 

[TPLYNCH]

Could also be a Torque Converter problem.

 

[97splorer]

turns out all five lug nuts on the rear wheel were loose. I tightened them all back up and problem solved.