E30 3 deg neg camber on rear wheel!

#1

Hello everybody. I have an 85 325e and wish the Spec series were here in Canada. However for now this is my track/street car.

No rust, and I’ve done a lot of maintenance items like motor/transmission mounts, driveshaft bearing and flex joint (that was fun). So here is my dilemma.

According to an alignment rack my driver’s rear has almost 3 degrees negative camber and the passenger side about 1 degree. The car has Eibach sport lowering springs. I don’t believe this car was in any kind of accident to warrant a bent control arm or the like, but it doesn’t seem like there should be that much negative camber on that side.

If I jack the car up by the body and then lower the body with the support of a jack on the rear crossmember I can watch the bushing/bolt move about 3/4" of an inch in. There is no banging or noise from the rear at all. I managed a 1.55 at Mosport GP track yesterday but I didn’t want to push more since all the wheels were out of whack. I can blame the dead lowering springs for the odd camber on the front, but my focus is the rear right now.

I came here and registered to get some information on whether bushings could cause the cross member to flex up and give the rear that much negative camber.

Looking at the rear suspension the travel up and down shouldn’t affect camber but caster at it rotates up and forward.

I’m interested in getting some feedback. Car is up in the garage so if you want some pictures of a particular area I’d be happy to.

An interesting note is that the odd drivers side control arm seems to sit hanging further towards the ground than the passenger side yet that same side has almost 2 degrees more camber. Doesn’t make any sense!

#2

Don’t have any information on the possible cause or the proper fix but I do have a car which also has 3 degree of negative camber on the passenger side rear.

Driver is is only about 2 degrees.

I don’t have any handling problems but the inner portion of tire do wear out faster on that side.

#3

All new bushings in the rear?

#4

That is a bent trailing arm, bad RTAB, or both.

If replacement of the RTABs (do subframe bushing and diff mount at the same time) doesn’t result in equal camber, replace the trailing arm.

#5

My driver’s rear is -3.4, passenger rear is -2.8.
(Front is -3.5 both sides)

So far, I’ve been happy with all this negative camber.
B) Fyi, I now have 26 heat cycles on my set of full depth R888s. I’ve rotated them around, and surprisingly, they seem to be wearing pretty even across the tread surface. And even with all the negative camber, I still get a touch more wear on the outside shoulder of the tread surface (not too bad, just concerned there’s a bit of rounding on the corner; I’ve been running 29-31psi).

#6

How the heck did you get -3.5 both sides front and stay within the rules? Is it really that easy?

#7

I put on some UUC camber plates and -3.5 was where it maxed out.

#8

Camber plates and offset upper shock mounts?