So back in October I had a pretty bad vibration that shook the whole car, expecially @ highway speeds, but only under acceleration. It was my U-joints, which were cracked and I replaced them with Rockford Driveline replacements (kind of a bitch to complete, but cheap!). Anyways. I also hung a new RB Road Race True Dual exhaust, added the RB Anti-Sways, plus Tockico Whites paired with RB springs. I've been driving the car around for a week or two and now I get a vibration that seems to be coming from somewhere around my transmission or father back at speeds above ~43. It gets worse in 5th gear, but then fades some after about 70-75mph.

What could be causing this vibration. I replaced my Trans. fluid with Redline MT90 before driving it, and my suspension is all torqued to spec (even after settling the suspension) although I suppose I could recheck.

Also, this new vibration occurs under accel and decel, even if I pop it in neutral once the vibration has started. This means it's probably not my trans, right?

 

sounds like your driveshaft might be out of balance... just an idea... dont hold me to it.

 

So I heard from a guy that I can put the rear of the car on jackstands and use 3 "hose clamps" on the shaft and use those to balance the shaft myself. Anyone heard about or tried this technique (in general or with a 7)?

 

take it off and get it balanced properly.... if that is indeed the problem.

 

Hose clamps might work, if you could know where to position them, which you probably can't without pulling the shaft and having special tools.

Yeah, I'd say most of the transmission is clear. When you're in neutral the rotors, half shafts, differential and drive shaft are all still spinning, as well as a small part of the transmission on the rear (with which I'm not intimately familiar yet, I don't know how much that output shaft touches inside the transmission). That said, first check all those parts that still move in neutral when you're rolling. You might have to pull them off. Also check all their mounts and mounting brackets for cracks, wear, wrong parts even or discontinuity between passenger and driver side parts that should match or mirror each other.