I have a 84 trans am. i have been having this loud vibration abouve 60mph for awhile. My transmission dropped to gears so i bought a rebuilt one and put it in ( I had the vibration with the bad transmission too). It didnt solve it. i put new u joints. same issue. I have had new tires put on and balance 4 times, that didnt solve it. I thought it could be the bearings in my rear end so I bought a kit and pulled the cover off. i found out that i broke numerous teeth off my ring and pinion. So I figured that was the issue. I bought a 9 bolt out of a 89 formula for 100 bucks. i took the cover off and inspected it and there was no wear on the teeth and everything looked good. But i still have the same issue. the engine is rebuilt and has about 15 thousand on it and i replaced all my engine and transmission mounts including the torque arm bushing. I am at a loss so any help would be nice

 

Have you had your driveshaft balanced??

 

GM often replaced D/S balance problems with an alum version (RPO JG1).

JamesC

 

no i havent. my brother made the suggestion to me but where i live nobody balances them. I was thinking about getting an aluminum one so i guess thats my next step. thank you