Subframe time

[HDdave]

Nice!

I personally wouldn't run Turner/ECS parts on my car, but if it works for you then by all means.

As for the rod bearings, I went with the WPC treated OEM set.

https://www.bimmerworld.com/Engine/E...aring-Set.html

I mean I have never had an issue with their stuff for hard parts.. And again its not like I a preserving some low mileage car, but you do raise a very solid point there with the bearings.. OEM coated does sound like a safer bet.

[old///MFanatic]

Was also thinking maybe the turner monoball RTAB? Or is that really not worth the money, and just do stock with limiters?

Anything else I should cover while I am in here? I know I will be dropping the fuel tank- should I preemptively just do the fuel pump too?

Yes would recommend monoball RTAB’s if you want a nice performace upgrade. And it is an upgrade over poly/limiters. Also all monoball RTABs are not created equal. I would suggest Syncro Design Works (SDW) monoball rtabs. They use a better OEM bearing and not a spacer.
As for fuel pump. You can do it while tank is dropped but really not much a time saver compared to when in the car. But if you’re for sure already planning to do it, now would be fine. But if your pump has been replaced before with Genuine BMW and not giving issues maybe don’t mess with it. FP is more a “run hours” thing, and if you have poor gasoline in your region that might compromise it. If the fuel filter has never been done I would do that.

[Cronenberged]

I wouldn’t run polyurethane on a street car or my track car, but to each their own. Stick with OEM rubber where it really matters. Rubber does a better job of absorbing and countering G-forces compared to poly or solid mounts. While poly and solid mounts increase NVH, softer poly can reduce it somewhat — but OEM rubber still offers the best balance for a street-driven car.

I’m planning to redo my rear end at some point, and here’s the setup I’m considering:

• Diff Carrier – CMP Solid Mounts
• RTAB – CMP OEM-style sealed articulating RTAB
• LCA – BW adjustable with OEM sealed articulating bushing
• Diff Bushings – OEM rubber
• FCAB – OEM rubber (sealed/greasable articulating versions also work well)
• Engine Mounts – Rubber mounts from 034 Motorsport (OEM-style, slightly stiffer)
• Transmission Mounts – OEM rubber

Just something to consider — if you’re going with spherical bearings, make sure they’re sealed, repairable and/or greasable.

[old///MFanatic]

If I had it all to do over again I'd probably go full Fall-Line on the car instead of mixing and matching.

https://ind-distribution.com/products/fall-line-motorsports-e46-e36-m3-trailing-mono-ball-conversion-kit?variant=19001074843717

I did post that all monoball RTAB are not created equal but $406 for these from IND seems like a huge money grab! I would like to know what about these makes them over $175 more than SDW, Condor Speed Shop (SDW makes it for them) monoball rtab’s. SDW uses OE Germany made sealed bearing that are machined so no spacers needed like some other brands. Also comes with Lifetime Warranty. Made and assembled in USA.

[Cronenberged]

I did post that all monoball RTAB are not created equal but $406 for these from IND seems like a huge money grab! I would like to know what about these makes them over $175 more than SDW, Condor Speed Shop (SDW makes it for them) monoball rtab’s. SDW uses OE Germany made sealed bearing that are machined so no spacers needed like some other brands. Also comes with Lifetime Warranty. Made and assembled in USA.

Fall Line tax

[enjoy_m3]

I just did an extensive rear end reinforcement/restoration on my touring. Vincebar on the trunkside/Reddish V3 plates on the underside. I went as far as coating the inner cavities of the RACP with antirust coating after welding the plates (if I had to do it again, the vincebar full epoxy kit would be better) for less risk of corrosion in the long term. I used fusor 2098 on my vincebar on top. You'll notice a big difference in how much better the rear end response and rides when Replacing the ball joints with new ones and using a monoball RTABs. I Used a meyle sealed ball joint RTAB from a latvian company, Rev-A. The car compliance is much better. I've also driven an m3 using the camry moog ball joints and it was compliant, no noise. Good alternative for the budget but does require minor modification. It's a lot of work, I'm sure Kevin (kaiv) can attest. Might as well replace the wheel bearings while it's out. It's a bit of a pain to replace without the right tools.I'd also advise against the ecs bushings. I've seen them back out after some time. I've gone with e36 m3 diff bushing pressed-in and have not had any issues on 4 cars. I've used revshift bushings and found them to be good quality for the price. AKG is also very good in terms of fitment. Good Luck!

[HDdave]

I did find a couple decent cracks in mine. Seem pretty in line with what I have seen from others. Drivers rear and pass front. I have a welder coming this morning to weld the plates in and fix the cracks.

[9kracing]

I did post that all monoball RTAB are not created equal but $406 for these from IND seems like a huge money grab! I would like to know what about these makes them over $175 more than SDW, Condor Speed Shop (SDW makes it for them) monoball rtab’s. SDW uses OE Germany made sealed bearing that are machined so no spacers needed like some other brands. Also comes with Lifetime Warranty. Made and assembled in USA.

SDW uses Lemforder bearings. Fall Line uses FK. The X3M guys are having their SDW monoballs fail after a minimal amount of miles. We are moving to AST.

I've always been a far of SDW, but after seeing their X3M products fail, I've moved on.



FWIW I asked ChatGPT why one would pick the Fall Line RTABs over competitiors.



The subtle design detail that makes the Fall‑Line Motorsports E46 M3 RTAB monoball kit better than most spherical RTAB conversions is how it controls articulation and load path, not just the bearing itself.

Here are the engineering choices that matter.

---

1. Misalignment spacers control the articulation angle


Most cheap spherical RTAB kits simply press a spherical bearing into the arm and bolt it in place.

Fall-Line instead uses precision misalignment spacers that:

• Limit the maximum articulation angle
• Keep the spherical operating within its optimal load range
• Prevent the bearing from “edge loading”

Why this matters:

The rear trailing arm on the BMW E46 M3 does not move through huge angles. When a spherical bearing articulates beyond its ideal range, it wears quickly and develops play.

Fall-Line’s spacers keep the bearing perfectly centered under suspension travel, dramatically improving durability.

---

2. Proper axial load support


RTABs experience both radial and axial forces:

• Radial load: cornering forces
• Axial load: braking and acceleration

Many monoball kits only support radial loads.

Fall-Line’s design:

• Uses wide spacers and housing geometry to distribute axial loads
• Prevents the bearing from taking thrust loads it wasn’t designed for

This reduces premature bearing wear.

---

3. Housing stiffness and geometry


The aluminum housing is CNC-machined with thicker wall sections than many alternatives.

This does two things:

• Prevents housing deformation under load
• Maintains perfect bearing alignment

If the housing flexes even slightly, the spherical bearing binds and wears out quickly.

---

4. NVH management


Despite being a spherical joint, Fall-Line’s kit tends to be quieter than many race RTABs.

Reasons:

• Tight bearing tolerances
• Correct articulation control
• Proper spacer preload

This is why many street + track E46 builds use them.

---

5. Why RTAB compliance matters so much on the E46


On the BMW E46 M3 rear suspension:

• The rear trailing arm bushing controls toe change under load.
• The OEM rubber bushing deflects significantly.

Under hard cornering:

• Toe changes unpredictably
• Rear stability suffers

A spherical RTAB like the Fall-Line eliminates that deflection, keeping rear toe stable during braking and corner exit.

---

💡 Fun E46 chassis fact:
BMW Motorsport used spherical RTABs on the E46 M3 GTR race cars, because rubber RTAB deflection was one of the biggest causes of rear toe instability on track.

[old///MFanatic]

SDW uses Lemforder bearings. Fall Line uses FK. The X3M guys are having their SDW monoballs fail after a minimal amount of miles.
I've always been a far of SDW, but after seeing their X3M products fail, I've moved on.

FWIW I asked ChatGPT why one would pick the Fall Line RTABs over competitiors.
1.Misalignment spacers control the articulation angle
Most cheap spherical RTAB kits simply press a spherical bearing into the arm and bolt it in place.
Fall-Line instead uses SPACERS
Fall-Line’s design:[*]Uses wide spacers
Despite being a spherical joint, Fall-Line’s kit tends to be quieter than many race RTABs.

Ok thanks for reply. But ChatGPT was replying about other brands on market, like cheap ones. Not comparing directly to SDW.
SDW has one of the best reputations on the E46 rtabs. Lifetime warranty. Also SDW doesn’t make rtab’s for the X3Ms. So for comparison, prob best to stick with E46s RTABs as the question at hand is our E46M3 RTABs. And longevity is widely documented and accepted for SDW with E46 monoball RTABs.
Of the ChatGTP stuff listed I see two things (I may be mistaken) related to Fall Lines vs SDW. One being different bearing brands used, and second being spacers. And Lemforder is OE for BMW and German made. So seeing that as a real positive. Also in research they are actually known to be quieter than FK. But FK does appear to be well respected for strictly racing applications. So for strictly racing I’d concede FK has advantage while for Sport/Street use, German made Lemforder has that advantage.
Next is that SDW uses these specific Lemforder sealed bearings that have the exact inside bore diameter so no spacer/sleeve needed. This is absolutely a plus. As sleeves and spacers are basically to fill in the incorrect tolerances of having to use a readily available size bearing already being produced (to keep cost reasonable). Although SDW does use a spacer for their “drift” rtabs to offset it. But spacers are not the optimal choice, nor are sleeves to make it fit where it was not directly designed for this particular fitment.
So with those points it’s hard to say Fall Lines are better than SDW. In fact for most applications it would likely be that SDWs are superior. And less expensive at that with Lifetime Warranty. I did not see Fall Line having a Lifetime warranty but could be wrong.

[9kracing]

I'm not saying SDW isn't good, or that one is better than the other.

Take from this what you will.

https://x3.xbimmers.com/forums/showpost.php?p=32633967&postcount=45

[old///MFanatic]

I'm not saying SDW isn't good, or that one is better than the other.
Take from this what you will.

Well it kinda seems like you’re saying SDW aren’t as good since you’ve brought up and stated, “I've always been a far of SDW, but after seeing their X3M products fail, I've moved on.”

As for what I take from your one post on a failed bearing:
RTABs ≠ Front Thrust Arms
E36/E46 ≠ X3Ms
Bearings using spacers are less optimal.
Good to have a product warranty! SDW does.
Good to have “replaceable” bearings in event a bearing premature/or under duress fails.

And of note, Rogue Engineering products are pretty well respected in the E46 M3 community. Guess what bearing RE use in their latest E46 RTABs? The same Lemforder no spacers/no sleeves needed.
Yes, it’s good to know if a company has a failure prone product. Even more so how they handle it with their customers.
I don’t have any reservations with SDWs RTABs lifetime warranteed product.

[9kracing]

Rogue Engineering products are pretty well respected in the E46 M3 community

You had me 'till here

[old///MFanatic]

You had me 'till here

😉 Well if that’s the only thing you replied about I guess my point was established.

[VinceSE2]

I did find a couple decent cracks in mine. Seem pretty in line with what I have seen from others. Drivers rear and pass front. I have a welder coming this morning to weld the plates in and fix the cracks.

As you might know the cracks are symptoms of a much larger underlying issue.

Please take a bit of time to watch this video that I recently put together.
It has been very well received.

https://youtu.be/SjomZVKZ_ko?is=Q2UAdPyec8oa6mXX

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