Bad vibration in rear under hard acceleration

[spaugh]

Ok i searched it seems alot of people have had this problem. Most of them were the carrier bearing. So i done the window weld fix and still same problem. I saw in one of the threads someone ask if the shifter knob moved at all. Well mine pushes back when I press the gas and pulls forward when I let off. When i was was under the car i saw the the front of the rear diff was wet with fluid were the shaft goes in. Is there a seal that needs replaced.

If you could help me i want to get it to the drag strip this weekend but i dont want to break.
Thanks for any help.

 

[HIGHPSI4]

Yea, need to fix the leak. As for the vibration, it still may be the drive shaft. Did you check the u-joints?

 

[spaugh]

I checked the u-joints the way that you check a RWD. Try to turn it while in gear and see if there is any play and wasn't any. Is there a right way to put the window weld in there. I just crawled back under there and couild still move the drive shaft side to side but not up and down.

Once again thanks for any help.