rear subframe bushing options

I am currently in the middle of resolving some rear subframe issues my 330i is experiencing and find myself needing to re-evaluate my options for subframe bushings. There are several available options that I know will work and one I believe should work but can't confirm. Here are the options I'm aware of:

1) 4 stock bushings
2) 2 front Meyle HD + 2 stock or Meyle rear
3) 4 stock M3 bushings (can anyone confirm whether these would work?)
4) 4 poly bushings from PowerFlex, UUC, AKG, etc

My subframe is reinforced with the TMS kit although I have developed a little crack along side a weld at the left rear mount. This is what I'm currently working to resolve and has me re-evaluating my choice of bushing. I believe I'm also experiencing a failure of the front left bushing - I had all 4 replaced with new stock bushings when the Turner reinforcements were installed several years ago.

In searching around, the folks at Turner, Bimmerworld, UUC, etc all seem to indicate that stiffer bushings help reduce the problems at the subframe mounts. I would tend to believe this considering the sources as well as my own logic tells me that stiffer bushings should force the other 3 mounts to carry there fair share of the load and keep so much load from being transferred to the left rear mount. There are a few folks though that seem to indicate the exact opposite so that leaves me a little uncertain as to whether I should really be considering going stiffer.

As for my upgrade options, I need to find out if the M3 subframe bushings are even a viable option as I've never run across any discussion of the possibility. Anyone know?

There was a recent thread reviewing the Powerflex subframe bushings but it only contained feedback from 2 people so I'm wondering if anyone else has any experience with these. Are the yellow (70A) suitable for a daily driver? Do they ever develop squeaks or need to be re-lubed? Do they have any hidden issues I should be aware of (for example, the PF on the e36 seemed to have some washer issues)? I've never been a big fan of poly bushings for automotive use so I'm a little leary of going this route. Unlike RTABs and CABs though, these bushings don't need to twist and in fact we'd probably like to make the subframe bushings as solid as possible while keeping ride quality and NVH reasonable.

Somebody please make a compelling argument for one solution over the others... I currently just

Originally Posted by TxZHP04

I am currently in the middle of resolving some rear subframe issues my 330i is experiencing and find myself needing to re-evaluate my options for subframe bushings. There are several available options that I know will work and one I believe should work but can't confirm. Here are the options I'm aware of:

1) 4 stock bushings
2) 2 front Meyle HD + 2 stock or Meyle rear
3) 4 stock M3 bushings (can anyone confirm whether these would work?)
4) 4 poly bushings from PowerFlex, UUC, AKG, etc

My subframe is reinforced with the TMS kit although I have developed a little crack along side a weld at the left rear mount. This is what I'm currently working to resolve and has me re-evaluating my choice of bushing. I believe I'm also experiencing a failure of the front left bushing - I had all 4 replaced with new stock bushings when the Turner reinforcements were installed several years ago.

In searching around, the folks at Turner, Bimmerworld, UUC, etc all seem to indicate that stiffer bushings help reduce the problems at the subframe mounts. I would tend to believe this considering the sources as well as my own logic tells me that stiffer bushings should force the other 3 mounts to carry there fair share of the load and keep so much load from being transferred to the left rear mount. There are a few folks though that seem to indicate the exact opposite so that leaves me a little uncertain as to whether I should really be considering going stiffer.

As for my upgrade options, I need to find out if the M3 subframe bushings are even a viable option as I've never run across any discussion of the possibility. Anyone know?

There was a recent thread reviewing the Powerflex subframe bushings but it only contained feedback from 2 people so I'm wondering if anyone else has any experience with these. Are the yellow (70A) suitable for a daily driver? Do they ever develop squeaks or need to be re-lubed? Do they have any hidden issues I should be aware of (for example, the PF on the e36 seemed to have some washer issues)? I've never been a big fan of poly bushings for automotive use so I'm a little leary of going this route. Unlike RTABs and CABs though, these bushings don't need to twist and in fact we'd probably like to make the subframe bushings as solid as possible while keeping ride quality and NVH reasonable.

Somebody please make a compelling argument for one solution over the others... I currently just

-I think thats because not that many poeple go that far, what I see going on on here is that people put rims and slam their car and when their subframe rips out they repair it under the recall and forget about it. Meaning there are VERY few people who actually go as far as replacing the rear subframe bushings.
-Yes, they are actually called "street" as opposed to black which are called "track" version.
-No you dont need to relube them. I nevent heard of anyone complaining about squeaks, and I searched on UK forum.
-I'm not aware of any hidden problems, they don not use any washers. They do use a bearing like tube in the middle(sleeve)
-Yes the OEM M3 will fit the non-M subframe 100%


Here is my argument, if you plan on doing this mod and we all know that its not a 10 minute filter change, lol, and it will require a pretty penny if you dont do it yourself or even if you do do it your self as it takes alot of time, so why not put the beck product in there so that you will never have to worry about it again. The thing about stock replacement is that you will be changing your old garbage for new garbage = money wasted. Myele are not really any better then OEM, and M3 ones are just a little tiny bit more rigid then then non-m.

When I did my research I couldnt find anyone using UUC subframe bushings, just a thought here.

You appear to be one of about 2 members on here who have actually installed poly subframe bushings of any brand... which also makes me wonder. How long have you had yours installed now?

Originally Posted by TxZHP04

You appear to be one of about 2 members on here who have actually installed poly subframe bushings of any brand... which also makes me wonder. How long have you had yours installed now?

I've had mine for one month now, about 1500kms and about 5 hours of track use.

Love em.

I'd feel better if there were more reports from people that had run them for years....

Anyone know anything about the subframe bushings from the BMW Motorsport catalog? They appear to be a bit over $200 a piece (if the part number lookup on Tischer is correct) so they're certainly not the most economical option. Are these just a much stiffer rubber design along the lines of the Group-N motor mounts or are they solid mounts?

I have about 8k miles on the PF yellow bushings. I got them risking that they would squeak but that was a trade off I was willing to make for buying something that will last a lot longer. What a PIA changing out these bushings. We know the OEM rubber bushings can fail pretty quickly with serious consequences...I don't want to worry if the rear floor of my car will fail.

I've gone with UUC poly RTABs and went back to OEM M3 RTABs. They squeaked and rode pretty rough.

In comparison, really have not noticed much of a difference going with the PF subframe bushings.

8k miles is a much better eval period than 1500 km but that's still only about 6 months of driving for me. I'd like to hear that they'll go 50-100k miles without cracking or deforming or needing to be re-lubed every 10-20k miles.

8k miles here in Korea is probably equivalent to 20k miles of suspension abuse in TX. The roads are AWFUL...worse than the northeast. You'll run over manholes sunk about 6" into the street, they pave the streets like that here! Oh, I launched my car over an expansion joint. The roads are frequently wavy so the car bounces all over the place. Although Koreans can repave a highway in a day...they do a crap job.

In addition, it goes from hot and humid like houston (more humid than hot here) to consistent sub-freezing temps. In between, you get monsoon rains. I've also spent about 5 hours on the track here in Korea as well.

Not sure if that helps.

BTW, yeah, Korea is a crap place to take a vacation. Go to China or Japan!

Heck, these days I don't even have time for a getaway weekend with the wife somewhere here in TX!

I would suggest searching on other boards, you wont find much help on here.

Try M3forum.net maybe.

Or maybe www.e46zone.com Powerflex is a UK company and UK guys love to buy their stuff. Just be careful when searching, those guys speak funny.

I've had solid aluminum subframe to chassis bushings for a year and a half now. No problems and not much extra noise. I really wish there were poly bushings for the diff to subframe bushings...

Originally Posted by vI6ious

I've had solid aluminum subframe to chassis bushings for a year and a half now. No problems and not much extra noise. I really wish there were poly bushings for the diff to subframe bushings...

Diff poly bushings would likely significantly increase NVH.

I think the issue with poly in the suspension is mostly squeaks...especially for RTABs...but really don't add a lot of NVH.

Poly in the driveline adds a lot more NVH. My vorshlag red engine mounts really added a lot of NVH. Especially buzzing when taking off from idle.

I think if you add poly diff bushings, you need to upgrade the rest of your driveline mounts as well. If your engine and tranny twists more than your diff, aren't you adding stress on your drivetrain components? I think I saw this on the vorshlag site.

yeah, I have already upgraded motor and tranny mounts, M3 guibo too.

I really need a 6 speed and M3 rear diff/subframe/axles etc...

Originally Posted by bigjae1976

Diff poly bushings would likely significantly increase NVH.

I think the issue with poly in the suspension is mostly squeaks...especially for RTABs...but really don't add a lot of NVH.

Poly in the driveline adds a lot more NVH. My vorshlag red engine mounts really added a lot of NVH. Especially buzzing when taking off from idle.

I think if you add poly diff bushings, you need to upgrade the rest of your driveline mounts as well. If your engine and tranny twists more than your diff, aren't you adding stress on your drivetrain components? I think I saw this on the vorshlag site.

Sorry for the thread bump--this thread has good info and I figured it'd be better to bump an older thread.

I wonder if extra vibrations that a stiffer poly subframe bushings transmits to the chassis causes the chassis metal to fatigue faster

Originally Posted by dreamdrivedrift

I wonder if extra vibrations that a stiffer poly subframe bushings transmits to the chassis causes the chassis metal to fatigue faster

No, stiffer subframe bushings should reduce chassis fatigue. Stiffer diff bushings may very well increase chassis fatigue though.