I have a BMW E21 320/6. Recently I have come across an issue with its front wheels coming out of concentricity. Mainly, my driver side wheel is too far forward. A problem that has existed since I got some front end work done to the car by a mechanic, which was then discovered myself during some work I was doing.
When I received the car, no issue was noted regarding wheel position in the arch. BBS spoiler was fitted which decreases arch clearance in the problem area, so for sure it was not a problem. Front end needed new springs and shocks, rear had been done by previous owner (odd?). I should note that from the offset, no peculiar chassis misalignment is noted and the car appears to be true in terms of alignment.
First Maintenance interval:
- top mount bearings
- front springs and shocks (only new back units was installed when I bought the car),
- reconditioned rack, Powerflex poly bushes installed.
- Work was carried out by a local mechanic
Post maintenance: Car drove fine, no problems with arch strike (I think). I didn't have the car on the road for that long, so it could have been an issue that wasn't solved and I just didn't notice.
Second maintenance interval:
NCT was carried out, found some worn track rod ends. I decided to change the wishbones also to the standard ones so I could get a retest quickly and not have any other questions asked of the assembly. Upon disassembly, I noticed the following as noted below (picture 1). An extra washer on the passenger side had been cut (green) and slid behind one of the washers on the front side only. Odd I thought! Wishbones were changed out and standard bushings left in (I was going to change them back to the Powerflex at a later stage)
Upon lowering the car, the arch striking issue began, passenger wheel was way too far forward, and was striking the arch. Bugger. By calculation, the thickness of the yellow and blue and green section above equals about 12-13mm (if anyone could verify this, it would be great). So a piece of stock was cut and flattened. This came to about 11mm and was inserted as below.
Comparison to driverside:
I am now getting struck on both sides of arches (PS + DS). PS is worse than DS, driveable but not liveable. Steering is loose enough, far looser than poly bushed wishbones (expected?).
- Is this due to the fact I don't have any washers present on the front side of the wishbone? If the wish bone gives slight flexibility, how does sandwiching it between two metal washers allow the movement to occur in driving?
- The wheels seem to find their own alignment after driving, reversing, turning etc. Is this due to the lack of washers on front end of wishbones also?
Apologies for the long post, but I figure this might give people a better idea of what's going on.