Vibration at 70mph after torsen install
 

Hey guys,I've searched for suggestions between here and m.net and have found multiple instances of this type of issue but no resolutions really.

I installed a torsen from a 95 with 75k on it into my 94 today (with energy poly bushings). Everything went smooth as silk and no issues apart from one of the two small studs from the lower mounting portion snapped upon removal.

Everything felt great during my test drive around the neighborhood but things changed once I got on the expressway to go home. Beginning around 70mph there is a substantial vibration throughout the entire car. It doesn't seem to match wheel speed,the vibration feels too rapid to be wheel speed which leads me to believe it coincides with driveshaft speed.

From my searching these are the things I've tried to no avail.

Re-installed my hub centering rings
Unbolted and flipped the driveshaft 180 degrees
Adjusted the ppf at the trans (I didn't loosen those bolts during installation of the diff) It was out of the spec I found online so i adjusted it,which didnt effect the vibration.

I'm just looking for anymore possibilities or suggestions to try tomorrow on my lunch when I can get it back on the lift. Also worth mention is between my previous vehicles that I had modded (95 Thunderbird,94 Probe,and 05 Legacy gt) each one had many poly bushings installed in various places and aside from more drivetrain noise I've never experienced an issue such as this so I highly doubt the poly diff mounts are the issue here.

Well just in case anyone runs across this in the future,adjusting the ppf a couple more times seems to have cured most of it. There is still the noise but I would absolutely say that its normal poly mount nvh. The massive vibration is gone at least.