Is there any advantage to using the spherical bearings from Fall Line Motorsport, Rogue Engineering, SPL, etc as opposed to the sealed Lemforder/Meyle/Bimmerworld/Future Classics style bearing? They are significantly more expensive.
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01-13-2026LAST POST
Street-cred - cool kids buy the big money SPL and Fall Line parts.
But seriously, no difference. Buy whichever you prefer. I'd say sealed is the way to go for sure.
But seriously, no difference. Buy whichever you prefer. I'd say sealed is the way to go for sure.
E9x does not have RTAB - it is multi link in rear 
I would spend more time researching our car’s suspension before rushing in and buying parts. No use throwing parts at a car unnecessarily.
In my perspective, only the following result in tangible improvements:
- Spherical front control arm bushings (get sealed).
- Solid subframe bushings.
- Diff bushings, yours are likely worn at this point. You can replace with OE, poly, solid depending on your use case and NVH tolerance.
- Adjustable rear toe arms with eccentric lock out.
Everything else, you’re spending money for very incremental improvements.
I know several people (including myself) who went full SPL adjustable arms front and rear and ended up regretting it. Be honest with yourself and how you use the car.
I would not go with unsealed spherical bushings unless your car is primarily for track use and you intend to service/greece the spherical bearings on a regular basis.
I would spend more time researching our car’s suspension before rushing in and buying parts. No use throwing parts at a car unnecessarily.
In my perspective, only the following result in tangible improvements:
- Spherical front control arm bushings (get sealed).
- Solid subframe bushings.
- Diff bushings, yours are likely worn at this point. You can replace with OE, poly, solid depending on your use case and NVH tolerance.
- Adjustable rear toe arms with eccentric lock out.
Everything else, you’re spending money for very incremental improvements.
I know several people (including myself) who went full SPL adjustable arms front and rear and ended up regretting it. Be honest with yourself and how you use the car.
I would not go with unsealed spherical bushings unless your car is primarily for track use and you intend to service/greece the spherical bearings on a regular basis.
Thanks for the replies.
Yea so I am doing an OEM+ refresh of the suspension, steering and bushings.
This question is specific to the bearings used in this OEM+ upgrade to the rear rubber bushings used in the subframe and hub carrier for the rear trailing arm and rear carrier/lower control arm as described here: https://www.m3post.com/forums/showthread.php?t=2223137
The rear trailing arm rubber bushing is was I refer to as the RTAB and the rear carrier arm rubber bushing is what I refer RCAB. If these suspensions don’t have rear trailing arm bushings or rear carrier/lower control arm bushings, what are the bushings that the rear trailing arms and the rear carrier/control arms connect to called?
In any case, For a street car, I did not see any practical advantage to using one of the premium priced options as opposed to the lemforder sealed bearing for this, and indeed, even if someone could articulate one, I would have sealed the bearing myself. You’ve both provided consensus on this. This is the answer I was hoping for, since the difference in price between the lemforder and the Fall Line for example is $200 v $1800, just for the 8 bearings.
I was not planning to use adjustable linkage components. I was planning to use OEM. The only changes I am making to steering and suspension linkage components are to press in spherical bearings in the front control arm bushings, as you mentioned, as well as the above spherical bearing upgrades to the OEM rubber bushings, using OEM arms. I was not planning on using adjustable toe arms in the rear, but when I was a looking at the full SPL/fall line/etc adjustable option, which I quickly ruled out for a street car, I concluded I would seal all of the unsealed bearings before installation. If I used adjustable rear toe arms I would do the same or possibly use the ground control offering, which comes with preinstalled boots, although I have read mixed things about the quality. Why do you suggest the adjustable rear toe arm with the eccentric lockout for the rear? Primarily for the assurance that the alignment won’t be affected under hard driving?
And yes, the subframe mounts are getting upgraded to aluminum as well as the differential bushings, I’m willing to take the risk on the differential mounts that the only major NVH will be the reported mechanical whine from the solid diff bushings.
I guess I should mention I am pulling the KW HAS sleeves on stock dampeners that I bought the car with and installing the Bilstein B8s from the B12 package with H&R springs. I have EDC and the ZCP. So the ride height will increase from where it currently is, but be slightly lower (.75”F/.25”) than stock.
The only other modifications I was considering were a bump steer correction washer kit for the front and hotchkiss sway bars. Even with the slightly lowered suspension and the adjustable sway bars, I still didn’t think adjustable sway bar end links could be necessary, but I could be wrong, that wouldn’t be hard to change out from stock however so I am not super worried about it.
When I do the rod bearings, I also plan on swapping OEM motor mounts for a comparable durometer poly option, same with transmission mounts, poly mounts of comparable durometer as well, for longevities sake.
Yea so I am doing an OEM+ refresh of the suspension, steering and bushings.
This question is specific to the bearings used in this OEM+ upgrade to the rear rubber bushings used in the subframe and hub carrier for the rear trailing arm and rear carrier/lower control arm as described here: https://www.m3post.com/forums/showthread.php?t=2223137
The rear trailing arm rubber bushing is was I refer to as the RTAB and the rear carrier arm rubber bushing is what I refer RCAB. If these suspensions don’t have rear trailing arm bushings or rear carrier/lower control arm bushings, what are the bushings that the rear trailing arms and the rear carrier/control arms connect to called?
In any case, For a street car, I did not see any practical advantage to using one of the premium priced options as opposed to the lemforder sealed bearing for this, and indeed, even if someone could articulate one, I would have sealed the bearing myself. You’ve both provided consensus on this. This is the answer I was hoping for, since the difference in price between the lemforder and the Fall Line for example is $200 v $1800, just for the 8 bearings.
I was not planning to use adjustable linkage components. I was planning to use OEM. The only changes I am making to steering and suspension linkage components are to press in spherical bearings in the front control arm bushings, as you mentioned, as well as the above spherical bearing upgrades to the OEM rubber bushings, using OEM arms. I was not planning on using adjustable toe arms in the rear, but when I was a looking at the full SPL/fall line/etc adjustable option, which I quickly ruled out for a street car, I concluded I would seal all of the unsealed bearings before installation. If I used adjustable rear toe arms I would do the same or possibly use the ground control offering, which comes with preinstalled boots, although I have read mixed things about the quality. Why do you suggest the adjustable rear toe arm with the eccentric lockout for the rear? Primarily for the assurance that the alignment won’t be affected under hard driving?
And yes, the subframe mounts are getting upgraded to aluminum as well as the differential bushings, I’m willing to take the risk on the differential mounts that the only major NVH will be the reported mechanical whine from the solid diff bushings.
I guess I should mention I am pulling the KW HAS sleeves on stock dampeners that I bought the car with and installing the Bilstein B8s from the B12 package with H&R springs. I have EDC and the ZCP. So the ride height will increase from where it currently is, but be slightly lower (.75”F/.25”) than stock.
The only other modifications I was considering were a bump steer correction washer kit for the front and hotchkiss sway bars. Even with the slightly lowered suspension and the adjustable sway bars, I still didn’t think adjustable sway bar end links could be necessary, but I could be wrong, that wouldn’t be hard to change out from stock however so I am not super worried about it.
When I do the rod bearings, I also plan on swapping OEM motor mounts for a comparable durometer poly option, same with transmission mounts, poly mounts of comparable durometer as well, for longevities sake.
I'm in a similar spot as you. I did an OEM+ front arm/bushing refresh a couple years ago (TRW kit from FCP) and it made a huge difference in the comfort/NVH, everything felt damped yet more responsive. Still on stock EDC but then I did solid rear sub-frame bushings and AKG 95A diff bushings (significant diff whine when above 100mph (track only)), but totally worth it for how planted the rear feels and how it puts power down.
Now I'm planning GAS monoball front control arm bushings and refreshing the entire rear. I came across https://groundcontrolstore.com/collections/e9x-e8x-rear-arms/products/bmw-e8x-e9x-adjustable-arm-set?variant=35876177539 but not sure if anyone has recent feedback or alternative suggestions besides SPL?
Now I'm planning GAS monoball front control arm bushings and refreshing the entire rear. I came across https://groundcontrolstore.com/collections/e9x-e8x-rear-arms/products/bmw-e8x-e9x-adjustable-arm-set?variant=35876177539 but not sure if anyone has recent feedback or alternative suggestions besides SPL?
Yea I saw the Ground Control rear arms. I read a few threads where people talked about them failing. I do like that they are sealed, but I figured I would just buy boots/seals and put them on an unsealed SPL or Fall Line.
With that said, since I am planning on pulling the KW HAS sleeves that I bought the car with and putting in the H&R springs with the Bilstien B8s (from the B12 kit) it will only be lowered about .75 up front and .25 in the rear from the stock ZCP suspension, so I feel like adjustable linkage adds an unnessary complexity.
I did however just burn through the almost new rear tires in about 3k miles on the setup I picked the car up with and I’m thinking it’s excessive rear toe in because the wear is even just excessive. So when I replace the rear tires and get an alignment this weekend, if they can’t get it into alignment with the stock rear toe arm and eccentric bolt, an adjustable rear toe arm may be in my future. I’m also thinking with the hotchkiss sway bars, adjustable sway bar end links might make sense, but we’ll see.
And even though I was asking the very narrow question of the difference between something like this:
https://www.fcpeuro.com/products/bmw-control-arm-bushing-lemforder-3147100005#description
And something like this:
https://www.turnermotorsport.com/p-5580979-lower-tension-arm-bearing-outer-e9x-m3e82-1m/
911r took it upon himself to mansplain to me that our suspensions “don’t have RBAC, they are multi link,” although they absolutely do have rear trailing arm bushings, the stock ones being rubber which I want to replace with a bearing, and proceeded to answer a question I didn’t ask (I guess he thought I was asking what advantage spl/fall line etc have over stock, which is not at all what I was asking) I would very much be interested as to why he felt there were “tangible improvements” from the adjustable rear toe arms. I’m assuming it is because of the eccentric lock out, since the stock arms use the sealed lemfolder/merle type bearing and not a rubber bushing, so presumably there wouldn’t be any reduction in deflection between the stock toe arm and an adjustable option.
But. he just kind of ghosted on the questions I specifically did ask him, after answering a bunch I didn’t ask, so perhaps we’ll never know.
With that said, since I am planning on pulling the KW HAS sleeves that I bought the car with and putting in the H&R springs with the Bilstien B8s (from the B12 kit) it will only be lowered about .75 up front and .25 in the rear from the stock ZCP suspension, so I feel like adjustable linkage adds an unnessary complexity.
I did however just burn through the almost new rear tires in about 3k miles on the setup I picked the car up with and I’m thinking it’s excessive rear toe in because the wear is even just excessive. So when I replace the rear tires and get an alignment this weekend, if they can’t get it into alignment with the stock rear toe arm and eccentric bolt, an adjustable rear toe arm may be in my future. I’m also thinking with the hotchkiss sway bars, adjustable sway bar end links might make sense, but we’ll see.
And even though I was asking the very narrow question of the difference between something like this:
https://www.fcpeuro.com/products/bmw-control-arm-bushing-lemforder-3147100005#description
And something like this:
https://www.turnermotorsport.com/p-5580979-lower-tension-arm-bearing-outer-e9x-m3e82-1m/
911r took it upon himself to mansplain to me that our suspensions “don’t have RBAC, they are multi link,” although they absolutely do have rear trailing arm bushings, the stock ones being rubber which I want to replace with a bearing, and proceeded to answer a question I didn’t ask (I guess he thought I was asking what advantage spl/fall line etc have over stock, which is not at all what I was asking) I would very much be interested as to why he felt there were “tangible improvements” from the adjustable rear toe arms. I’m assuming it is because of the eccentric lock out, since the stock arms use the sealed lemfolder/merle type bearing and not a rubber bushing, so presumably there wouldn’t be any reduction in deflection between the stock toe arm and an adjustable option.
But. he just kind of ghosted on the questions I specifically did ask him, after answering a bunch I didn’t ask, so perhaps we’ll never know.
oldmanjingles wroteI think https://www.fcpeuro.com/products/bmw-billet-trailing-arms-with-monoball-set-btae9xkt might the best value, same 6061 as other companies. Fall Line's set is also only 2 arms vs. 3 from Ground Control, so I'd have to mix a new OEM arm w/ rubber + 2 monoball? Nothing against them, I have their DCT pan and have been eyeing a rear diff cover but an extra ~$150-300 for each pair of arms over other brands feels like I could better spend that elsewhere. My local shop steered me away from upgrading the rear sway bar FWIW, just did powerflex bushings while in there & up front, made everything quiet and smooth.Yea I saw the Ground Control rear arms. I read a few threads where people talked about them failing. I do like that they are sealed, but I figured I would just buy boots/seals and put them on an unsealed SPL or Fall Line.
With that said, since I am planning on pulling the KW HAS sleeves that I bought the car with and putting in the H&R springs with the Bilstien B8s (from the B12 kit) it will only be lowered about .75 up front and .25 in the rear from the stock ZCP suspension, so I feel like adjustable linkage adds an unnessary complexity.
I did however just burn through the almost new rear tires in about 3k miles on the setup I picked the car up with and I’m thinking it’s excessive rear toe in because the wear is even just excessive. So when I replace the rear tires and get an alignment this weekend, if they can’t get it into alignment with the stock rear toe arm and eccentric bolt, an adjustable rear toe arm may be in my future. I’m also thinking with the hotchkiss sway bars, adjustable sway bar end links might make sense, but we’ll see.
And even though I was asking the very narrow question of the difference between something like this:
https://www.fcpeuro.com/products/bmw-control-arm-bushing-lemforder-3147100005#description
And something like this:
https://www.turnermotorsport.com/p-5580979-lower-tension-arm-bearing-outer-e9x-m3e82-1m/
