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Poly RTABS or Rubber OEM RTABS Lemforder

31K views 83 replies 13 participants last post by  rkneeshaw 
#1 · (Edited)
Guys I have researched and gotten mixed reviews. I definitely prefer ride comfort over extreme stiffness.

I am getting the H & R Touring Cup Suspension Kit so that should def stiffen the handling but I am not sure if I should add the Poly RTABS.... Overkill?
Also heard the Poly's squeak even with the grease after a few months and it seems that people prefer the OEM Rubber Lemforder.

Any help and guidance as always will be most appreciated.

*If Poly, than best brand, best website to purchase?

*If OEM rubber, than best brand, Lemforder or Mele and best website to purchase?

:thumbsup:
 
#2 · (Edited)
In my humble opinion, poly is junk for high-demand, high-activity bushings. Go OE/OEM design such as Meyle HD for both FCABs and RTABs. You can also do Lemforder RTABs. Easy in easy out with correct tools. No maintenance needed and you don't have to be under your car looking for creaks and squeaks. The bones in your wrist also won't rattle out.

Try oembimmerparts or bmaparts.

GL
 
#5 ·
I had powerflex in my vert and I didn't notice the ride changing at all. My RTAB's weren't shot to begin with and the only difference I felt was more grip in the rear end. It sorta felt like I added more weight to keep the rear end stable. For $80 and a $80 install I was very satisfied.
 
#6 ·
I had a hell of a time trying to fit the oem lemforder m3 rtabs into my housings for some reason, one just did not want to go in. Had the tool and everything, ended up bending the rod of the tool. So I gave up and ordered powerflex. Decently priced... same price or cheaper than oem+limiters, and honestly not harsh at all really. Rear end feels more planted, just make sure you grease em up alot. No squeaking or anything so far...
 
#7 ·
For people who like the feel of rubber, the RTABs are the one place where it is acceptable to go poly. The NVH difference (RTABs only) is so small that if you didn't drive your car for a week in between you would not notice a difference.

Powerflex or AKG. AKG makes a part that is slightly softer than Powerflex and apparently cannot be distinguished from stock rubber. Stock rubber with limiters is more of a PITA than it's worth. Yes, I've tried that solution also.
 
#8 ·
Poly can be unpredictable in the RTAB location due to binding. Yes, this is according to Vorshlag. But if you understand how the BMW rear suspension is designed, there has to be play in that location. It's designed that way on purpose for street cars. BMW calls it elasto-kinematics (12th time I am mentioning this very word/term on these forums here @ e46fanatics.com) and is a huge part of the success story of world-renowned BMW 3-Series handling and stability.

Plus.. I wouldn't want to deal with the noise. I just think poly is often installed because it is "easier" to deal with than bushings. But in my opinion, they aren't.

I doubt the BMW M3 CSL is buzzing around the Nurburgring with poly RTABs. In fact, I know they're not. They use standard M3 part# 33326770817. It's preference, of course, but I'm saying don't think that it automatically will make your car grip harder or drive faster cause it won't.

Just don't get the obsession with poly when BMW designed the entire suspension to be elastic, including the hardcore M3 CSL. I just think that money is better spent elsewhere like on the CSL-specific rear lower control arm that uses a spherical bearing on its inner pivot rather than a bushing. The same can be had with aftermarket control arms that have a bearing like TMS. Now that I'm sure would give you some "feel" :evil:
 
#10 ·
I have powerflew rtabs in my 03 m3 ad I haven't had a problem since I installed them two years ago. You won't notice too much difference between the stock and poly unless ur really pushing it. That said poly will last longer than rubber which is a big reason why I bought them.

I also bought PF FCABs and so far they have been a disappointment. The passenger side has been riding up the control arm. I have to reseat it and see if it works.


Sent from BimmerApp mobile app
 
#11 ·
i think because you don't have a high HP car and also your weather is the type that your cars will see snow. i would go with rubber bushings, but upgrade to the M3 ones and maybe limiters.

i have the poly ones and have no issues or squeaks. love them. but in climates that see varying weather with salt and water i might be worried about it's effect on the bushing and grease. then you might introduce possibility for squeaks. which means you have to lube them again compared to maintenance-free oem style rubber bushings.
 
#12 ·
Hello BMW Experts!
Add one more vote for Poly RTABs. I had M3+limiters, which lasted ~ 40k, and were quite beat by then.
UUC has what might be the softest Poly RTABs, which is what I recommend. They also have very nice grease grooves, which should help keep them lubricated & silent.

Murf :woot:
 
#28 ·
umm unless i'm ready this wrong this is all the same thread and it's not even due to poly rear trailing arm bushings. that's the E36 issue and happens to stock bushings
 
#23 ·
Oh, Oh! Ball joints, sounds like NVH to me. Mango, go with the mushy squishy 323 stock rubbers all around! They be what BMW planned for you to do. :lmao:

Murf
 
#24 · (Edited)
I've never heard of Powerflex Bushings failing except in that one post Mango has supplied. Mine are absolutely okay. The NVH is mildly increased. The ride is stiffer. My RTABs have developed a squeak though. I don't have anything bad to say about PU bushings structurally. Having said that, I will be buying Meyle HD FCABs and Lemforder RTABs w/ limiters whenever I decide to replace these (if ever). There aren't any major advantages to the PU bushings other than longevity. I think limiters mostly solve that for the RTABs and the Meyle HD FCABs are supposed to last quite a while now I think.
 
#36 ·
I just don't get the dislike of poly bushings when nobody can provide any evidence that there are real problems with them. I don't see the poly RTAB causing problems with binding either. The OEM bushing moved at most a few degrees during the full travel of the wheel. The poly RTAB still provides compliance. It is just stiffer. My car with poly FCABs and RTABs rides over all sorts of bumps perfectly. I don't hear anything weird nor do I feel anything that I could attribute to binding. Everything else I hear about PF bushings is positive (minus the squeak issue). Only Vorschlag and yourself seem to have a problem with them.
 
#39 ·
Aside from the potential binding ESPECIALLY on a stock suspension, if you haven't reinforced your subframe mounting area to any degree yet, I'd be very careful at those stiffer bushings (by your own admission) causing extra unnecessary forces on your subframe mounting area.

Further, if you want stiffer, extra feel, etc., why not change out your trailing arm bushing on the RLCA outer to a balljoint rather than bushing? That will give you meaningful BMW ///M-tuned precision stiffness rather than jamming in a plastic bushing, IMO.
 
#63 · (Edited)
I vote Powerflex Poly. I used the bigger (66mm I believe over the stock 60mm FCAB's) and RTAB's. After 2 years they are still doing great with NO noise.
My stock rubber RTAB's and FCAB's were so worn that they chewed up the inside of my tires. The RTAB's were also a pain to get out and the FCAB's had sand in them. I put the Poly in and it made the car feel tight and elastic instead of Sloppy and loose. Now the only thing going wrong in my steering is the stock rubber coupler which I will change for an AKG motorsport Poly coupler. The roads here are nice so I don't care about the added NHV (which I have noticed slightly when switching to Poly. But now I feel connected to the road better and it isn't by any means uncomfortable.) I know I could have felt the same results If I switched to rubber but, After seeing how rotten the rubber was on my car and hearing other people complain about the short lifespan that rubber bushings have compared to Poly. Well......I chose Poly. And I would choose it again. Although by the condition of the Bushings now.......I won't have to in a long time.

My 2 cents.
 
#65 ·
Hello BMW Experts!
AKG has lots of Poly RTABs, some specified for track, some for both, & some for street only @ 85A. The softest poly RTAB still seems to be from UUC @ 75A. Being moderately sane, this is what I got.

Murf
 
#68 ·
Sorry if I seemed a little rough as well. I don't want anyone to think it's my way or the highway. There are a few "issues" which i am passionate about. This being one of them. I'm sure you all have great experiences with your poly rtabs. I just think it isn't necessary and goes against the whole BMW design philosophy. Believe it or not, the Vorshlag opinion is very well written and makes a lot of sense. There's obviously enough truth to it that this debate happens in the first place. This debate is on every forum. I am still convinced a big reason people install the poly rtabs is because it's "easier to deal with." Would you guys that installed poly rtabs install poly engine/trans mounts? I wouldn't give much grief in those locations because the mounts just sit there and aren't subjected to the same forces and directions the trailing arm bushing is.

Since Alex has the RTAB tool, he probably installed the poly rtabs for performance/feedback reasons. but for most other people, I don't think that was the case.

LittleBear and WDE, how did you remove your stock rtabs?
 
#82 ·
I have researched some of the grease used on the poly bushings such as Marine grease, white lighting or copper lube... Any thoughts which one is the best or most effective to eliminate the squeaks.

I'm installing my POLY RTABS today and would appreciate the quick feedback.

I did not see much info with the search button....Thanks for the help in advance....
 
#83 ·
Someone help me understand this:

The limiters install on each side of the RTAB, limiting movement. Don't they prevent that side-to-side movement that Mango is saying is key to proper suspension articulation as much if not more than poly RTABs?

So how is OEM+limiters all that different from poly RTABs when it comes to this "binding issue"?
 
#84 ·
I guess that last post was a stumper.

I've since removed my RTAB limiters and installed PowerFlex poly bushes. Even with the limiters, my stock bushes wore out and were causing some squirm in the back of the car. So I replaced with the setup with the powerflex RTABs.

Overall I really notice zero ill effects. I will comment that with just the right kind of bump in the road it will feel slightly harsher than it used to, but 99% of the time the only thing different from the setup with limiters is a nice solid rear end.
 
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