My U-joints went bad around 90,000 miles. Basically, the U-joint connects to the drive shaft. Your drive shaft should be tight and steady. If you grab your drive shaft with two hands. Try moving it back and forth. It shouldn't move at all. If it does, your U-joint needs to be replaced.

Also, if the back of your car shakes in the rear suspect the U-joint. Go 20-30 miles per hour, the car starts shaking, release your foot off of the gas, it should ease shaking. If this happens, you have bad U-joints.

Peace.
Tom
012009