Aluminum Control Arms?

E28 technical advice asked and given! Troubleshooting, modifications and more.
kendogg1
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Post by kendogg1 »

I found aluminum lower control arms on ebay for $122 shipped, thast about the same as the stockers are. Are these any good, you think, and are they better than stock? There is 17 hours left on the auction, and there are 9 sets available too, I believe.
L_N_Love
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Post by L_N_Love »

There was a post here recently by someone who did a lot of front-end work ...used alum. lower control arms and had a bad overall result. After trying several remedies he replaced the alum. lower control arms with OEM and the problem was resolved.I would say go with OEM.
louielouie
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Post by louielouie »

I've had the E34 control arms for ~ 30k miles and they haven't been a problem. Scuttlebut has a rumor of the soft aluminum getting sloppy around the ball joint... YMMV
FastFiver
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Post by FastFiver »

I have aluminum E34 arms on right now. No problems, and reduced weight make them pretty enticing. Good luck with the install.
fastpat
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Post by fastpat »

[QUOTE="kendogg"]I found aluminum lower control arms on ebay for $122 shipped, thast about the same as the stockers are. Are these any good, you think, and are they better than stock? There is 17 hours left on the auction, and there are 9 sets available too, I believe.[/QUOTE]

I have them. They were OEM on the e34 M5. They're forged aluminum, not soft aluminum.
Image

Mine are OEM Lemforder brand and have 5-6000 trouble free miles on them. Check with the seller for the brand name.
stuartinmn
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Post by stuartinmn »

I bought some off eBay a year or two ago, they were OEM Lemforders. The word I've heard is Lemforders are good, other brands are suspect.

I haven't put mine on yet, but I managed to get them really cheap so I figured it was worth getting them and putting them away until I need them.
Aaron from Aus
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Post by Aaron from Aus »

Thoughts on buying a second hand set of these Aliminium lower control arms?

I can get some sets cheap from a spares place...i dont think they would sell them if they where no good... but thought id ask you guys Anyway.
MarkD in NJ
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Post by MarkD in NJ »

The problem with a second-hand set of aluminum arms is that you can't replace the ball joints. The ball joints on the steel arms are replacable. This goes for E30/E36 arms also.
C.R. Krieger
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Post by C.R. Krieger »

IMO, using aluminum control arms on the E28 suspension is kinda' like peeing yourself in a brown suit: You get a nice warm feeling, but nobody notices ... :p
greg.epps
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Post by greg.epps »

[QUOTE="C.R. Krieger"]IMO, using aluminum control arms on the E28 suspension is kinda' like peeing yourself in a brown suit: You get a nice warm feeling, but nobody notices ... :p [/QUOTE]

:D :D :D :D :D :D :D :D ROFLMFAO!!!!!

Maybe I'm tired at the end of a long work day, but that was FUNNY!
shifty
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Post by shifty »

[QUOTE="C.R. Krieger"]IMO, using aluminum control arms on the E28 suspension is kinda' like peeing yourself in a brown suit: You get a nice warm feeling, but nobody notices ... :p [/QUOTE]

Yeah, but you could say the same thing about buying an E28 to get noticed in, too!

Besides, I remember FastPat mentioning on the MyE28 board a couple of years back about how the reduction in unsprung weight doesn't make THAT big of a difference, but every time he's under that area of the car he has some eye candy. He didn't use that wording, but you get the point. A lot of us clean the engine bay and the underside of the car (super clean wheelwells, anyone?) because of the satisfaction we get in seeing that area of the car nice and clean when we're working there.
Duke
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Post by Duke »

I would NOT buy them off of ebay. I bought a set from ebay and they looked good and installed easy. A year later the ball joint in the right one was bad and the car would not pass the safety inspection here in Germany. I went to the dealer and bought a replacement. The dealers part was a much better quality than the crap I got from ebay. Now, the left ball joint is now bad and I will be replacing the left control arm with OEM BMW after the engine install.
fastpat
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Post by fastpat »

[QUOTE="Aaron from Aus"]Thoughts on buying a second hand set of these Aliminium lower control arms?

I can get some sets cheap from a spares place...i dont think they would sell them if they where no good... but thought id ask you guys Anyway.[/QUOTE]

I would not buy used lower control arms unless I could verify their condition on the car. The ball joints aren't generally replaceable and the bushings should be replaced as a matter of course.

New is much better. :)
shifty
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Post by shifty »

[QUOTE="Duke M535Ti"]I would NOT buy them off of ebay. I bought a set from ebay and they looked good and installed easy. A year later the ball joint in the right one was bad and the car would not pass the safety inspection here in Germany. I went to the dealer and bought a replacement. The dealers part was a much better quality than the crap I got from ebay. Now, the left ball joint is now bad and I will be replacing the left control arm with OEM BMW after the engine install.[/QUOTE]

Were those the Lemforder brand or were they the "other" brands that the others on this thread were referring to?

Steve Haygood sells Lemforder aluminum CAs. Or, at least he did a year or two ago.
louielouie
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Post by louielouie »

This basic p/n (31121139991 for left lwr) is used in the E24, E28, E32 & E34. The E32 didn't get spec'd with the aluminum part.. Maybe there's a reason for that... ~0
fastpat
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Post by fastpat »

Neither the e24 nor the e28 had aluminum lower control arms installed from BMW, only the e34 M5 had them. :) They're the same size in the critical fastening point dimensions, and are lighter and possibly stiffer (some would argue this last point) than the steel arms.:cool:

I'm not absolutely certain, but I think the e32 control arms are different, probably longer. :p
Shawn D.
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Post by Shawn D. »

[QUOTE="Shifty"]Were those the Lemforder brand or were they the "other" brands that the others on this thread were referring to?

Steve Haygood sells Lemforder aluminum CAs. Or, at least he did a year or two ago.[/QUOTE]

The aluminum LCAs I got from Steve a couple of months ago are of undetermined provenance -- they're not Lemforder.
shifty
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Post by shifty »

[QUOTE="fastpat"]I'm not absolutely certain, but I think the e32 control arms are different, probably longer. :p [/QUOTE]

The E32 control arms are definitely different. I think Rex said they would require a bend to mount them onto an E28. He compared them to his E28 arms at one point to see if using them was possible.
Walt
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Post by Walt »

I got this at 5er Fest from CCA tech advisor Carl Nelson, who has 2 M5s and a little repair shop in So. Cal.

Because the wear direction isn't on the axis with the ball joint, but slightly at an angle, typical compression testing for play, with big channel locks may give a false positive. There can be a wear pocket you don't feel with the pliers.

The result can be unanticipated failure, and typically, very much increased dificulty in removal.

Carl was removing them from his wife's 3.8L e28M5 in favor of OEM steel. The reduced weight was the sole advantage, and not worth it in his opinion His mechanic took about 5 minutes on one side and over an hour on the other. Both "felt" fine, but were worn upon closer inspection of the socket.

YRMV
Walt
Threeshifter
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Post by Threeshifter »

The stock e28 front suspension is quite light to begin with, hence the super road sensitivity and sensitivity to shimmy and wobble. Unless you are building a performance or track dedicated car with other sophisticated front suspension upgrades I am guessing that you probably will not notice a difference except that your wallet might be lighter with the aluminum arms.

Most of the potholes that I drive over dont seem to mind my stock steel OEM arms.
fastpat
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Post by fastpat »

I know Carl Nelson, and while he may have taken aluminum arms off a car, the only reason to do so was that he didn't want to pay for the replacement aluminum arms.:)

There is no reason NOT to install aluminum arms, they are better than steel because they perform the same function at lighter weight, and that alone makes them better. :cool:

Aluminum lower control arms are simply a premium component, a choice among several choices. :D
Walt
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Post by Walt »

I replaced mine and bought the parts from him. He could have talked me into more expensive aluminum LCAs but didn't.

Perhaps he's too cheap to pay for premium parts for his own car (although it doesn't appear he cuts many corners there) but you'd think as a business person, he would try to maximize sales dollars and sell up, especially to a performance leaning customer.

Pat, I don't think his actions support your premise of a cost driven decision. The money (particularly at his cost) is not that significant.

His theory of wear may differ from yours, and you may well have more experience with worn aluminum LCAs.

I certainly defer to experts on this one. For now, I'm not prepared to sacrifice suspension durability (potential, or otherwise) for minimal gain. Everyone makes compromises and I've made many.

Walt
a very compromised 535
fastpat
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Post by fastpat »

Walt, perhaps you misunderstood him. Of course, I can't speak to an anecdotal event that may have had a one time effect on his particular car. %)

The aluminum arms don't wear faster, the ball joint doesn't bear on the aluminum, it's pressed in at the end, the ball joint is self contained and wears at the same rate as the steel ones do. I can't say for certain, but I'd be surprised if Lemforder, who makes both steel and aluminum arms, put weaker ball joints in the M5 component and a better ball joint in the steel unit.

Wouldn't you? :)
Shawn D.
Beamter
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Post by Shawn D. »

We all know that the "experts" can be fallible. While Carl Nelson is obviously a respected authority in BMW circles, a person can't be right about everything. When I purchased my Suspension Techniques sway bars from him, I asked about the need for reinforcing the mounting points. He said he'd never seen any failures and that it wasn't necessary to do any reinforcing. Now, how many of us would agree with that? :)
fastpat
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Post by fastpat »

Carl's major expertise has always been in the older BMW's; particularly the e9, e3, and 2002. He's gotten into later models over the last few years, selling his coupe and buying his e28 M5's. I ordered "all" the parts to install a 5-speed in my e9. I didn't receive all of the parts, and one I did receive was incorrect. He made good on it, but he's fallible, just like the rest of us. :)
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