PlaneCrazy

Good to know.. Thanks.. And dam.. I wanted to order the SLP loudmouth

Is this something I need to do like right now? Or just don't speed so much?!

GP-1

Well, I guess that would be your call.. I figured that a u-joint was gonna break at some bad time, so I wanted it done ASAP..

jbird

Yeah, switching a driveshaft isn't a big deal. It's about like changing oil, lol, maybe easier. You should also put in new u-joints. That will make your job a little more difficult, but it's well worth the effort. I busted a u-joint in an old ford pickup once w/a two piece driveshaft. The rear shaft fell out and got all bent up. I had to have a new one made. It was a pain. So, while you have it out anyway, you might as well do that.

It also could be a worn tranny mount, not quite busted, but worn. When you're on the throttle the engine is trying to push the tranny one direction, when you're off (engine braking) the tranny is trying to push the engine backward in essence, but really just exerting force in the opposite direction, which means the tranny is trying to turn a different way. (May just be my sleepy ramblings, lol, I didn't get in bed last night) Maybe someone else can confirm this. Anyways, when you're on the gas, the tranny is putting pressure on the mount one way, and when you're off the gas, the tranny is pushing the mount the other. Someone chime in and let me know if I'm right.

If I were you, I might try to change the tranny mount first because it is cheaper than a new shaft. You'll be p@ssed if you get a new shaft and the vibe is still there. Could this also be a u-joint going bad? Again, maybe someone else will chime in here.

Hope this helps. ---J.Bird

ShiftyCapone

Could going over bumps and just cruising cause this as well. I have a horrendous fast clunking coming from the center console at speeds above 40 while crusing. It will clunk for a minute at a time sometime at only 65mph. I will often hear it if a bump is big enough at slow speeds as well.