I have a 1995 Nissan ex-cab 4x4. When you drive it at 35 to 40 mph the rear end shakes like a tire that has a belt broken in it. But when you push the clutch in it stops and the shake quits. I had a guy tell me that I need to replace the u-joint. But before I do that I want to know if that sounds like my problem. The truck sat for a little over 2 years outside. If you throttle fast and get above 40 mph quickly you can't really tell it but if you drive normal it gets on your nerves. Thanks for your help.