Rear tire wear?Why??

[kentish]

Hi there,

Which worn part can cause an excess camber at the rear apart from the 4 trailing arm bush?


Regards
Kentish
540ia

[George M]

sagging springs or lowering springs will automatically dial in more negative camber and affect rear toe...the biggest contributor as the suspension both front and back subtends an arc as viewed from front and back as it traverses from full jounce through normal driving position into full rebound. Lesser players are worn subframe and/or pitman arms...trailing arm bushings lead the bushing category and are available in eccentric shape to offset this tendency.

[Messerschmitt]

I have had the same problem with my 1994 530i. After replacing all of the "common" parts I decided to go further. I replaced the mounts for the rear differential. They consist of three rubber mounts like the suframe mounts only smaller. They made the most difference in real "feel" than anything alse that I replaced. The rear felt tight "like new" and the wear seemed to slow down dramatically! Not an easy fix but a cheap one if you don't count your time! Let me know if you need more info.
Messerschmitt

[50 fiver]

What are the "common" and what parts do you replace in the rear end at 200k? I believe some bearings may be going, but I haven't checked them yet. Do you know what parts I should be looking at for the front end? I have already done springs,shocks,thrust/control arms, and outer tie rods. But some of the boots have torn already. Thanks

[George M]

Good information Messerschmitt. Most on the board have not addressed these bushings and quite possible they are a major contributor to overall stability of the rear suspension. Could you elaborate a bit on where the bushings are relative to the diff housing? What is involved to change these three bushings? Easy or tough job? Is it simply the bolts that retain the diff to the car?
Thanks.

[Bill R.]

all on the camber...
Assuming he's talking about the top mount on the diff and the 2 round rubber mounts on the sides.





QUOTE=George M]Good information Messerschmitt. Most on the board have not addressed these bushings and quite possible they are a major contributor to overall stability of the rear suspension. Could you elaborate a bit on where the bushings are relative to the diff housing? What is involved to change these three bushings? Easy or tough job? Is it simply the bolts that retain the diff to the car?
Thanks.[/QUOTE]

[George M]

agree...in theory they should have no effect on rear suspension geometry...only efficient power transfer from the driveshaft to the diff to the halfshafts by solid location of the diff....so curious as well what bushings had an influence on tightening the rear of the car up.

[Messerschmitt]

After replacing everything on the front end of the car, the loose feeling in the rear became more apparent. I decided to play a little and replace the rear sub-frame mounts. They made a huge difference but the car still didn't have that new feel. I dicided to bite the bullet and order the rest of the bushings for the rear end. I still haven't installed trailing arm bushings, but I went ahead and installed the three round rubber bushing on the diff. mounting. They made a very significant difference. The car had developed a loose feel (sort of like having soft snow tires on the rear all of the time). After installing these three bushings the squishy feel was completely gone. Even my wife noticed the difference. I have already posted a procedure and some pics of this job, just do a search using my username.

Messerschmitt