Ive had alittle bit of a roar in the rear of the car since I bought it. Last week I bought a LS1 driveshaft and put a new rear Ujoint in it and installed it. Afterwards I took it for a test drive and noticed the roar seems worse so and Im getting a vibration at 65-70ish mph. I came home and changed back to the stock driveshaft with a new rear Ujoint and Im getting the same exact same. Its strange that this wasnt that bad till I took the driveshaft now its horrible, Ive checked and double checked it and had the shaft out several times and cant find anything. it does it under throttle and at coast at 70 mph. Im down to guessing its the rear wheel bearings or pinion bearing but need any opinions. I also had the torque arm off the rear to get the driveshaft out, is there anyway to get the pinion angle off with the stock torque arm?

 

oil on flywheel or bad pilot bearing ??