Control Arm Bushings

GregT53 · 22nd December 2011, 00:26

The control arm bushings are shot so I need to get them replaced. My car has 52K miles and the bushings are simply suffering from age. The shop I took it to for an estimate wants to replace the whole assembly instead of just the bushing. They told me that pressing out the old bushings and pressing in the new was a difficult procedure that may damage the assembly so they include new asemblies ($200ea) in the estimate. Funny thing is that they recommended I use polyurethane bushings which are aftermarket and would have to be pressed in. This sounds like a pile of bs to me but I'm new to the M5 so maybe I'm missing something here.

davidoli · 22nd December 2011, 00:38

Hi Greg and welcome to the board .

If you were sticking with the stock rubber control arm bushes , then I would agree with your shop and replace the whole arm , both upper and lower , as the ball joints can wear also .

However , as you are considering fitting Poly bushes , then I would simply press out the originals and replace with the polys .

D

vitomir · 22nd December 2011, 13:36

I have Control Arm Bushings aftermarket powerflex,and other parts of the suspension is powerflex,i m satisfied. the car is much more sensitive to the wheel, it is much stiffer in cornering

mottati · 22nd December 2011, 18:50

i've had poly bushings in a street car and always have come away thinking i crossed the line away from good streetability. Too much noise, harshness and eventual squeeking. You can press new bushings into the arm.

For control arms, i used the e31 part, it's aluminum, like the the oe M5 plus it has a speherical bearing instead of a rubber bushing. For thrust arms, you can typically press in a new bushing into the old arm at least once. After that, the ball joint is probably getting to the point of wear such that it's best to just replace the entire arm.

As an aside on parts prices, if you have the part number (easily gotten off realoem.com) you can plug that into the parts seller i have listed in my sig. This is an internet arm of my local dealer and they're usually pretty good with pricing.

GregT53 · 23rd December 2011, 00:58

Quote:

Originally Posted by mottati

i've had poly bushings in a street car and always have come away thinking i crossed the line away from good streetability. Too much noise, harshness and eventual squeeking. You can press new bushings into the arm.

For control arms, i used the e31 part, it's aluminum, like the the oe M5 plus it has a speherical bearing instead of a rubber bushing. For thrust arms, you can typically press in a new bushing into the old arm at least once. After that, the ball joint is probably getting to the point of wear such that it's best to just replace the entire arm.

As an aside on parts prices, if you have the part number (easily gotten off realoem.com) you can plug that into the parts seller i have listed in my sig. This is an internet arm of my local dealer and they're usually pretty good with pricing.

Mike,
Thanks for the helpful information, including a link to your parts supplier. I am glad to know that the bushings can be pressed in at least once especially since my car only has 52K miles on it. I suspect the ball joints are good for at least another 50K. The mechanic I'm using is an old timer who knows his way around the E34s and in particular the M5. In fact, he mentioned the same thing to me about the steetability of poly bushings saying precisely the same things you said about harshness and noise, and the extra stess on the non-poly joints. His point of view is that the German engineers who desgned the M5 probably thought about what they were doing very carefully and he saw no good reason to mess with success.
Greg

David L · 29th December 2011, 16:41

At one point I replaced my OEM (rubber bushings) with Poly (Powerflex - purple ones if recall). I know powerflex makes a few "flavors" but mine wore out very quickly in the front. I ended up going back to the OEM rubber (similar philosophy of your mechanic), BMW engineers make some pretty good stuff.
PS. I only replaced the bushing (I recall it took some effort to get the powerflex out of there, but the control arms were still fine to reuse).

GregT53 · 30th December 2011, 02:52

I'm going with the OEM part and the repair will be made next week. Thanks for your reply. I know lots of owners like the Powerflex replacements but for me the OEM stuff is plenty good!

stija · 30th December 2011, 05:16

Personally i would replace the whole arms, ball joints and everything. It's gotta be economically feasible especially if you are not doing the work yourself. OEM parts of course....exactly what i did with mine and it had ~75miles.