850csi control arms?

[bfd]

On the UUC digest, Rob Levinson responded to a question about replacing the upper control arm and using the 750i bushing on an 1989 E34 535i. Rob's response was:

<Mythbuster time: E34 M5 bushings are stronger than 750iL bushings. Use those.

The problem is the ball joints themselves may be bad - you won't know until you replace the bushings. If the problem remains, you've got to do it all over.
Ideally, you'd start with new arms with M5 bushings, or even the 850CSi aluminum arms with the OE spherical bearings, direct fit in the E34. A bit more
expensive at around $250-ish each.>

So, a few questions:

1. Has anyone here replaced their upper control arm with ones from the 850csi?
2. what is the OE spherical bearings?
3. do you still have ot put in the M5 bushings?

I have a 90 535i, 5 spd with 96K miles and at some point will need to "refreshen" my suspension bushings. If this is feasible, it sounds interesting.

[632 Regal]

I would assume that replacing the thrust arm "bushings" with "bearings" would cause an enourmous amount of roadnoise and a jarring comfort level to say the least.

If you are only concerned about Tracking the car I'd say go for it, if you plan on driving it I'd say to stick with a bushing. The 750 bushing is stiffer than the standard one and ride quality suffers a small amount but is still very acceptible. The 850 is probably stiffer since it is for an even heavier car.

[Mobius]

I've seen metal bearings used in the lower control arms - but not in the upper/thrust arms. I'd agree that a metal bearing in the thrust arm would be.. really harsh..

That said, according to: http://rust.mine.nu/bmw/showparts.do?model=EG93&mospid=45095&prod=19931000&btnr=31_0222&hg=31&fg=05&x=144&y=85 (1993 850CSi) the thrust arm bushing is "rubber" - and the control arm+bushing is only $180 so..

[bfd]

I've seen metal bearings used in the lower control arms - but not in the upper/thrust arms. I'd agree that a metal bearing in the thrust arm would be.. really harsh..

That said, according to: http://rust.mine.nu/bmw/showparts.do?model=EG93&mospid=45095&prod=19931000&btnr=31_0222&hg=31&fg=05&x=144&y=85 (1993 850CSi) the thrust arm bushing is "rubber" - and the control arm+bushing is only $180 so..

OK, it appears the upper control arm bushing, whether its 750i or M5, is rubber. However, could the "OE spherical bearings" that Rob is referring to be on the ball joint side of the control arm? Thanks.

[bfd]

Also, I wouldn't trust the prices on that website. Instead, get the p/n and call BMA!

[Mobius]

Also, I wouldn't trust the prices on that website. Instead, get the p/n and call BMA!
Seeing as how their sales system isn't up yet, that's what they're expecting you to do.

Parts prices on there pretty much seem to be dealer cost.

[ryan roopnarine]

i don't know why this person would recommend the 850CSi arm, unless there's something different between the 850i and 850csi, or about the balljoint that i don't know about (other than it being for a heavier car). I asked someone with an 850i if his bushing was different than the ones he was pressing in for me, to which he replied that the 750i bushing looks exactly like the one he replaced on his car. i guess i'll have to ask to see under his car the next time i'm over there. also, before anyone asks, the e32 arm is too long to fit an e34, been through a whole box of mixed e28 e32 e34 thrust arms at shantaram used bmw parts in toronto.....but the balljoint didn't look any beefier on the e32 part than on the e34 one.