Who's RTAB is better? Bimmerworld/Syncro Design/TMS

[r4dr]

BTW thanks again so much for link.
Didn’t see where the bearing/balljoint was taken out to see the brand. Only noticed one showing one outside pressed in view of some visible (perhaps unrelated) numbers that don’t show up in a Google search.

I've never seen a ball joint from Lemforder or any other OEM that BMW uses with clear plastic boots... not that this is scientific, but it doesn't look right and the result was clear.

That being said, CMP cites Lemforder p/n 3067901 as the ball joint used if you need to replace it. I can't really find that on any US-based parts site, including RockAuto or Google. The part number is hard to cross-reference too, I ended up at a FCP page for a Meyle E9X ball joint but I'm not sure if that's correct.

[K-Dawg]

I've never seen a ball joint from Lemforder or any other OEM that BMW uses with clear plastic boots... not that this is scientific, but it doesn't look right and the result was clear.

That being said, CMP cites Lemforder p/n 3067901 as the ball joint used if you need to replace it. I can't really find that on any US-based parts site, including RockAuto or Google. The part number is hard to cross-reference too, I ended up at a FCP page for a Meyle E9X ball joint but I'm not sure if that's correct.

From https://cmpautoengineering.com/pages...-the-pros-cons

This is where our Monoball RTA bearings come in. Within the purple 6061 aluminium housing is a brand new BMW OEM bearing made by lemforder (No. 3067901). This bearing is the same diameter as the bearing between the E46 RTA and upper control arm that supports the weight of the vehicle meaning it's more than up for the task and and was originally used in the rear suspension of the E9X/E8X/X1

I hadn't tried to locate the bearing before I ordered the bushes.

[r4dr]

Yeah, that's where I got the Lemforder p/n. Just couldn't find anything outside of random Lithuanian eBay listings that sold the part with that reference. Just curious, since I'm always wary of finding custom parts down the line in 10 years when the original company isn't around anymore.

[K-Dawg]

Same. Now I wish I had tried to source the bearing before ordering the CMP RTABs.

Some more discussion of these bearings:

https://www.m3post.com/forums/showthread.php?p=26799013

https://www.1addicts.com/forums/show....php?t=1615006

[r4dr]

Those threads are good finds. Worst case is that Meyle part.

That 1Addicts thread is interesting. If you scroll down to where he uses a Bimmerworld kit to replace a rubber bushing, it's a bearing that has the same clear plastic boot as the ones we've seen fail in this thread and the one I linked. He found it difficult to move that ball joint and it matched the behavior of a cheap aftermarket arm. Turns out he bought OE BMW arms to get better bearings.

Fool me once...

[old///MFanatic]

Geez I must have used the worst Search words possible because I always do a search for threads before and these threads did not appear in my inquiry.

So unanswered before, now hearing there are some notables difference in these brands.

[oceansize]

Geez I must have used the worst Search words possible because I always do a search for threads before and these threads did not appear in my inquiry.

So unanswered before, now hearing there are some notables difference in these brands.

I chose CMP because I went down this rabbit hole. He lays out on his site that he is using a Lemforder bearing and I had to pick who to trust. As much as he contributes I can't see him telling tales.

[fattycharged]

SDW from FCP


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[old///MFanatic]

Interesting info in the other threads. Especially Terra’s break down on the differences in the brands and the bearings and some modifications those bearings needed to fit.

Found interesting how info presented about BW’s bearing brand back then. According to those statements in threads it was supplied by OCAP and claimed a cheap India knock-off.
Looked them up and OCAP actually is a steering & suspension parts company that is OE for Mercedes Benz. Based throughout Italy(with other plants around the world). Company has parts carried by many, even by FCP Euro (who selectively carry high quality parts since they offer a Lifetime Warranty). Makes carried by FCP Euro include BMW, MB, Land Rover, Audi. So yes they are a European-OEM supplier. Well sure, that doesn’t mean this particular mono ball wasn’t faulty. But supplying for MB sure isn’t like it’s some obscure brand with little quality control. Just saying.

I do not know what brand they use now. If that was the issue or if it was an issue of being pressed in housing by the inner races and not outer.

[old///MFanatic]

SDW from FCP

Now I’m starting to lean towards the SDW. Not sure if their description that their unit uses a plastic sleeve at the bearing is unique. But they state this prevents the bearing metal to metal that causes clunks. As some other brand mono ball users/manufacturers claim increases harshness when going over reflectors, potholes, etc.
I had spherical heim joints on my E30 M3 back on the day and they do transmit metal to metal on impacts that’s unpleasant.

[fattycharged]

Now I’m starting to lean towards the SDW. Not sure if their description that their unit uses a plastic sleeve at the bearing is unique. But they state this prevents the bearing metal to metal that causes clunks. As some other brand mono ball users/manufacturers claim increases harshness when going over reflectors, potholes, etc.
I had spherical heim joints on my E30 M3 back on the day and they do transmit metal to metal on impacts that’s unpleasant.

I have them on my e36 M and they are silent, no comment on my e46 as I haven’t installed, but would have no qualms about it.


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[George Hill]

I've installed a bunch of CMP and SDW and have never observed personally or heard of a customer noting a noise.