I have a 2002 Dodge Dakota 4x4 Quad Cab. Starts to vibrate in rear on acceleration around 45 to 55 mph. Stops vibrating when coasting but when I hit the accelerator quickly and release, there is a load clunking coming from the rear end of the vehicle. I had the rear differential rebuilt about 4 years ago to take care of a growling noise.
I think this may be U-joints. Is there another way to verify if it is the U joints and not something else?
The only way to confirm this would be to remove the drive shaft from the differential and inspect it for wear. The clunk would be an indication that there would be wear in the joint and or the differential bearings. Going by what you said about the rebuild on the differential having a bearing issue is probably unlikely. I would go with the faulty universal joint inspection first.