“This is not surprising,” notes BimmerWorld’s James Clay while looking at the cracked and worn bushings. “These bushings are under about the most stress of any in the car, especially under hard braking, and the stock ones are way too compliant to begin with, so when you star…
I recently put delrin bushings in and when I went to the alignment shop the toe was over 1" out of spec since the rubber bushings has squished out of the arms and deformed so much from the stock geometry.
One thing I found out in the process is that some cars depend on bushing compliance for some multi axis loads. Derlin is entirely non-compliant of course. So that means you can potentially limit adjustment range in some circumstances. My car the rear lower control arm has the rear pivot as non-adjustable with a double wishbone arrangement. That makes that joint a pivot for the rear camber adjustment. The answer is probably a spherical bearing just for that location, but nearly every maker of bushings for the car just includes a solid bushing there, including very reputable ones.
Of course with less camber loss to bushing flex I'll probably need less camber over all, but something to watch out for when you're looking at replacing them. I'll have to update on tire wear later.
The E39 has the same thrust arm bushing problem. Nearly two decades later and it's still around?
Keith Tanner said:The E39 has the same thrust arm bushing problem. Nearly two decades later and it's still around?
That legendary German determination at work
theruleslawyer said:I recently put delrin bushings in and when I went to the alignment shop the toe was over 1" out of spec since the rubber bushings has squished out of the arms and deformed so much from the stock geometry.
One thing I found out in the process is that some cars depend on bushing compliance for some multi axis loads. Derlin is entirely non-compliant of course. So that means you can potentially limit adjustment range in some circumstances. My car the rear lower control arm has the rear pivot as non-adjustable with a double wishbone arrangement. That makes that joint a pivot for the rear camber adjustment. The answer is probably a spherical bearing just for that location, but nearly every maker of bushings for the car just includes a solid bushing there, including very reputable ones.
Of course with less camber loss to bushing flex I'll probably need less camber over all, but something to watch out for when you're looking at replacing them. I'll have to update on tire wear later.
Yeah this is definitely becoming an issue with the current SCCA rule allowing substitution of non-metallic bushings as more and more multi-axis bushings get introduced into use by OEMs. That original rule was written back in the day where you just threw a set of Energy Suyspension urethanes into your stock bushing holes and went about your business. But now so, so many cars use multi-axis bushings and there's not really an off-the-shelf solution for those that meets the current rules (which are actually 40-year-old rules).
Keith Tanner said:The E39 has the same thrust arm bushing problem. Nearly two decades later and it's still around?
By the E90 era the 3 series front suspension became a double pivot strut setup very similar to the E34 / E38 / E39 front suspension. I'm not sure how much they've changed it since the E90 though.
That looks like the alignment kit from the https://calipergarage.com/. I have that too. I've used it on two cars now. Great piece of gear!
Enchanter said:That looks like the alignment kit from the https://calipergarage.com/. I have that too. I've used it on two cars now. Great piece of gear!
It is indeed (I know a guy).
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