Thought it was a bad drive shaft U-joint at first. They checked out ok. The vibration is there from take off until about 40 mph then it just goes away. there is quite a bit of lash in the diff gear. Could that be causing the problem?


Thanks.

 

Double check those U joints. You might not see it. With everything loose, put your finger on the gap between the ears and rotate the shaft back and forth. (shifter is in neutral with the wheels chucked). Feel for any play. Any at all is not OK. Also, pull off the freeway, park and feel for heat. Any dry/bad bearing will heat up. (that includes the needle bearings in the U-joint cap)

 

Good idea on a temp check. I will give it a shot. No movement at all at the u-joint connection point.

 

I was getting a vibration on acceleration up to about 45-50mph............I suspected U-joints, but when I checked for play, there was none.........
The vibration got worse and worse...........All the signs told me it was driveshaft U-joints, so I bought new ones............
When I went to take the old ones out, all the needle bearings fell out as a dry metal dust...............