Rear Diff/Beam position

Need technical Q/A then you're in the right place

Moderator: martauto

Post Reply
wildeian
E30 Zone Regular
E30 Zone Regular
Posts: 851
Joined: Thu Mar 09, 2006 11:00 pm
Location: Colchester, Essex

Sun Dec 07, 2008 6:06 pm

I changed the complete running gear from my Sport to my Touring just over a year ago, and I've just noticed something (possibly) strange.

I've been having cyclic (whum-whum-whum...) noises coming from the rear for a little while now, which increase with speed. (It didn't happen just after the transplant)

I've changed a few things - Discs, calipers, front bearings and I'm in the process of changing the Prop. I stripped out all the heat shielding and put everything back together to get a better idea of where the noise was coming from.

It appears to be coming from the prop itself, about 3 inches infront of the UJ at the rear diff. There is scoring around the prop, and looks like it has been rubbing on the little bracket the fuel tank slots into.

Now - Looking down the transmission tunnel towards the Diff, the Diff is offset to the drivers side through the hole in the rear beam. I also can't see the top of the hole in the rear beam, as the fuel tank mount is in the way.

Could my Diff or Rear beam be mounted too high, or is there anyway to lower the diff in its bracket? (3.91 LSD)

I'm hoping changing the prop will sort this out, as it's the only original part of the Touring left, and its UJ is pretty stiff.

Any advice welcome! :D
(Sorry I didn't have a camera to hand, would've saved about 3 paragraphs!!)
daimlerman
**BANNED**
Posts: 15968
Joined: Mon Feb 27, 2006 11:00 pm
Location: Grumpy Old Man

Sun Dec 07, 2008 6:52 pm

Could it be rear beam bushes have collapsed?
Youth is wasted on the young.
wildeian
E30 Zone Regular
E30 Zone Regular
Posts: 851
Joined: Thu Mar 09, 2006 11:00 pm
Location: Colchester, Essex

Sun Dec 07, 2008 8:59 pm

I changed one on the transplant, the other looked fine.
Post Reply