Vibration in driveline after rear end locked up

[jhobins]

Hey guys, I've got a 2002 2500 hd with the nv4500 5 speed transmission.  A few days ago while driving on the highway my rear end started whining pretty bad.  I pulled off at the next exit, and when I went to take off the truck lurched forward hard and slammed back, I think the rear momentarily locked up.  After getting it into a parking lot, I checked the fluid which was very low.  I added fluid and attempted to drive it home.  The rear end no longer made any noise, but now there is a strong vibration in either the trans or driveshaft when I apply the throttle.  If I leave it in gear and coast there is no noise and no vibration, but as soon as I touch the gas the noise and vibration comes back.  Does this sound like a twisted driveshaft?  Or did I break something in the transmission?  

[Mikebtte]

It sounds like an issue in the rear end!! If I read correct you added fluid to the rear end "which was very low" and the locking up went away. The Rear diff will not bounce back from an issue by adding oil. I would remove the rear cover and inspect the Diff and go from that point. The rear diff can cause vibration. The entire Transmission back to the diff needs to retain the correct angles in order to be smooth and the bearings in the diff housing running dry will reverberate and increase up the driveline.

 

Not to say you did not mess up something in your transmission or driveline, but I would fix the main issue and diagnose after that point.