Has anyone installed the M3 Diff?

[jonnyd330]

So I saw someone selling a full M3 diff swap for non-M cars. Anyone on here done it?

http://forum.e46fanatics.com/showthread.php?t=1048147

Just wondering what this entails an how much I can expect to spend on extra parts. I would want to do a bushing refresh while everything was out. What else would I need to do for maintenance?

[slater]

lots of folks have done it. but, at that price - which is $1200 really, as you need the driveshaft (he offers them) - i'd go for the MFactory diff. then you get a NEW diff, for not much more money, and it's compatible with everything you've already got.

[NoVAphotog]

lots of folks have done it. but, at that price - which is $1200 really, as you need the driveshaft (he offers them) - i'd go for the MFactory diff. then you get a NEW diff, for not much more money, and it's compatible with everything you've already got.

+1

Same thought process I had...considered M3 rear end...went with brand new Mfactory diff. Happy Camper, significantly less work, brand new diff, OEM+ car still instead of M3-ish frankencar.

[jonnyd330]

I see both of you run the 3.46 LSD. Is that is the popular ratio to run?

[wertyu78]

Go with Diffsonline. Race proven, 100% Made and Warrantied in the USA, and 100% awesome. As close to OEM as you can get and a quality warranty standing behind it.

www.diffsonline.com

[ELCID86]

+1

Same thought process I had...considered M3 rear end...went with brand new Mfactory diff. Happy Camper, significantly less work, brand new diff, OEM+ car still instead of M3-ish frankencar.

+2

3.38 FTW


---
"ZHP is a garbage option anyway- just some cosmetic upgrades with a different cam and diff to claw back some of the performance lost fitting those hideous and heavy wheels. Any 330 with a 3.46 diff will smoke a ZHP every time. The whole Mafia thing reeks of childish behavior." - an e46fanatic

[slater]

I see both of you run the 3.46 LSD. Is that is the popular ratio to run?

the gearing is enough of a difference over the 3.07 to be noticeable, without sacrificing highway driveability.

the added grip is nice, too.

[jonnyd330]

One of the reasons I was looking at doing the M3 diff was allegedly that setup would change the offset for our rear wheels. So this meant I could potentially run M3 rear wheel sizes. I would really like to run some Volk TE-37's and it seems like they are more commonly available in M3 sizes.

[wertyu78]

One of the reasons I was looking at doing the M3 diff was allegedly that setup would change the offset for our rear wheels. So this meant I could potentially run M3 rear wheel sizes. I would really like to run some Volk TE-37's and it seems like they are more commonly available in M3 sizes.

This is true, but you could also order the wheels in the offset you are looking for, fitment wise. If the wheel manufacturer is limited on offset availability, you can always have a machine shop touch up on them for you.

The viscous limited slip unit in E46 ///M diffs is nothing to brag about. You'd be a lot happier with a true mechanical clutch type diff (just like the E36 M, E30 M, and several other cars.

IMO, the real benefit in an E46 M subframe and diff is in how the diff is mounted, with two ears on the most rear facing part of the diff, and more options for fluid cooling.

[slater]

One of the reasons I was looking at doing the M3 diff was allegedly that setup would change the offset for our rear wheels. So this meant I could potentially run M3 rear wheel sizes. I would really like to run some Volk TE-37's and it seems like they are more commonly available in M3 sizes.

well, the M3 also has much larger-flared wheel arches - so you'd be in for a guessing game at that point.

The viscous limited slip unit in E46 ///M diffs is nothing to brag about. You'd be a lot happier with a true mechanical clutch type diff (just like the E36 M, E30 M, and several other cars.

IMO, the real benefit in an E46 M subframe and diff is in how the diff is mounted, with two ears on the most rear facing part of the diff, and more options for fluid cooling.

these are excellent points, wyatt - i didn't even think of the mounting. nice.

still though - you're right about the diff. there are better options out there.