S52 swap with UUC flywheel - shakes like hell!

[treff-7]

i also thought about misfire or some sort of failure in the engine but it shook off throttle as well and there was no power loss. also it idled smooth as butter and the wrx sound was only inside. engine and exhaust sounded just fine.
so i ended up jacking it up and taking a look at it this evening and turned out the transmission was in fact touching the chassy so i took the cross member off and held the tranny a little lower with a hydraulic jack and tadaaaa! no more shake! so i shimmed it lower and now it doesn't shake anymore. my car officially became a MONSTER! 8-)
Thank you all for the help!!!

[treff-7]

Manual mounts. I have a new set of each and the E30 ones are softer.

That's weird.... i have a new set of each as well and i find the e21 softer. maybe i don't have the part i think i have???

[Leo_328i]

Is it possible that the flywheel has been installed whilst not properly clearing the alignment dowel?

Had an M52B28 that had an incorrectly positioned aftermarket flywheel on it which shook the shit out of the car and it would be consistent with engine revs. That motor is now totally stuffed after driving a few hundred kms on it with that situation.

Imagine that the flywheel should sit flush with the engine, or upright if you were looking at the car's driveline from it's side. Mine didn't clear the dowel properly and was slightly wonky, so when the engine was rotating it really shook the shit out of the car.

[treff-7]

Is it possible that the flywheel has been installed whilst not properly clearing the alignment dowel?

Had an M52B28 that had an incorrectly positioned aftermarket flywheel on it which shook the shit out of the car and it would be consistent with engine revs. That motor is now totally stuffed after driving a few hundred kms on it with that situation.

Imagine that the flywheel should sit flush with the engine, or upright if you were looking at the car's driveline from it's side. Mine didn't clear the dowel properly and was slightly wonky, so when the engine was rotating it really shook the shit out of the car.

I'm sure it was installed correctly. i payed extra attention to the dowel when installed it. i heard some of the aftermarket flywheels don't have the bigger hole for the dowel and it needs to be removed before install.