last month I put a new diff 3.73 in my car (matched with dogleg box). soon after i started to get this occasional high pitch noise coming from the back. thought it was the diff. the guy i bought it from exchanged it to another 3.73 for me which i put it this morning. (75W90 Redline oil also).
after a 10 minute drive the noise came back and stayed on during the 20-30 minute drive. i then jacked up the car and had my friend accelerate while i listenend underneath. the noise is coming from behind the passenger rear wheel. comes on roughly around 40kms/hr.
COULD ANY OF THIS CONTRIBUTE TO THIS:
1) the centre bearing i pre-loaded as much as i could by hand towards the engine and then tightened the bolts. (when i put the car back together after my mini restoration)
2) did a whole heap of painting the rear subframe/axles (could some paint have gone in and somehow damaged something...worth cleaning anything?)
also what other E30 will match the output shaft with the M3?? cheers for the help fellas