Aluminum solid Differential and Subframe Bushings Review (Macht Schnells)

[e46m3tony]

the subframe on my 2011 E93 was recently damaged from a bad differential bushing, so i ended up swapping out the whole rear subframe out with another one from an used BMW M3. In the process i decided to go with Solid aluminum bushings for the differential and subframe.

the reason i chose Macht Schnell Solid aluminum bushings was because they were in stock at EAS. I have driven the car for around 200 miles so far, and there is a definite increase in noise. it is the differential whine noise. it is a little annoying with the music off, but.... i usually listen to my music really loud. i knew this was a possibility going with solid aluminum DIFFERENTIAL bushings. don't really notice any increase in vibration, or harshness. very daily drivable.

other than the whine noise, every thing else is fantastic. the car feels more solid, and the handling feels way better ( i also installed eibach pro kits in the process).

if i had to do it again, i would probably go with power flex, or the derlin/aluminum differential bushings. but i definitely recommend upgrading those rear differential bushings to something more solid; or at least keep and eye out for worn out differential bushings.

[JEllis]

What tool did you use to swap out the bushings?

[flipm3]

Thanks for sharing!

When the time comes, I'll definitely be doing the solid subframe bushings.

I am still undecided on what to do for differential bushings. I suspect that Polyurethane and Delrin will still have substantial whine for daily driven, low volume music, and a quiet exhaust.

Looking forward to hearing more feedback!

[e46m3tony]

Originally Posted by flipm3

Thanks for sharing!

When the time comes, I'll definitely be doing the solid subframe bushings.

I am still undecided on what to do for differential bushings. I suspect that Polyurethane and Delrin will still have substantial whine for daily driven, low volume music, and a quiet exhaust.

Looking forward to hearing more feedback!

I feel that polyurethane might not have that much noise, since it would be metal to rubber contact as opposed to metal to metal contact. But I can't comment on that. I might swap out the differential bushings for poly one day if I'm bored haha.

[flipm3]

Originally Posted by e46m3tony

I feel that polyurethane might not have that much noise, since it would be metal to rubber contact as opposed to metal to metal contact. But I can't comment on that. I might swap out the differential bushings for poly one day if I'm bored haha.

Oh yeah! I certainly agree that it would be less. With the E46 M3s that I've done Polyurethane diff bushings on, there is still a very faint whine. By no means as crazy as solid, but still present.

What tool are you using to press all of these out?

[7500rich]

So you have solid rear subframe bushing and differential mounts, and stock engine and transmission mounts?

Is there any concern about using solid on one end and not the other? I am looking at the turner solid subframe and diff mounts and they mention you wouldn't use solid in one place and non-solid in another (I think referring to engine/tranny/diff).

Maybe someone can fill me in on acceptable combinations of mounts.

[Hujan]

I have solid subframe mounts (MRF) and Delrin diff mounts (Turner). All work done by MRF. The rear end feels absolutely amazing, but I do get more diff whine than I care for. I wish it was 30% less.

I've been told that it is significantly less with poly mounts than Delrin. I am tempted to swap out the Delrin with poly and perhaps go with poly trans and engine mounts at the same time.

[pbonsalb]

That way you can move the objectionable for a driver noise up front from the rear.

[wrecklessfool]

Originally Posted by JEllis

What tool did you use to swap out the bushings?

Do a search for the OP's started threads. He just did a DIY write-up a week or so ago. He used a variety of tools/parts to complete the job and ultimately bought a 12-ton press from Harbor Freight to complete the subframe bushing install. I just did this myself over the past few days WITHOUT a press or the proper tools and it was a major bitch. A huge undertaking without the proper tools. I made all kinds of crazy contraptions; a different method for each of the bushings. Just tried stuff until I came to a solution. Removal was by far the hardest part. Install was a bit easier because I used my lessons learned from the removal to facilitate the install. I tried to use a press but could not get the ears of the subframe to seat in a position I was comfortable with. Haven't had a chance to drive the car yet as I still need to bleed the brakes. My recommendation would be to rent the tool from HP Autosport for $60. I would have if there was not a wait for it. The differential bushings will still require a little ingenuity as I believe the HPA tool will not work for them. Feel free to PM me your number and I can give you some advice for a DIY install.

[flipm3]

Has anyone had experience with this?

http://www.kochtools.com/index.php?p=product&id=242

[wrecklessfool]

Originally Posted by flipm3

Has anyone had experience with this?

http://www.kochtools.com/index.php?p=product&id=242

Didn't see this when I was looking for the tool myself. Nice find! It should work based on what it says it fits. I know a lot of the 1 series guys are running M3 subframe bushings and the other E9x non-M's also run them too so the sizing is correct. Can't imagine the subframe is too different around the mounting areas so I think you would be alright. But keep in mind that HPA rents the tool for about $60. If you replace the bushings with solids then you can consider this a one time use tool. Just something to consider