Which 6 Speed Transmission for e34 M5

[Layne]

.. $108k

Too expensive.


What car are we talking about here? Used clutches are always a bad idea, BTW.

[E34GRRR]

Too expensive.

What car are we talking about here? Used clutches are always a bad idea, BTW.

Donor car is 2002 M5 w/108k miles
Tranny was $600
EBay seller w/ 100% positive feedback
Says clutch is tight. Asking $150.. could probably scoop for $100.

My car is 95 540i/A w/ 137k mi.

[Layne]

Ahh ok. I would never buy a used clutch for any price, but suit yourself. The only thing to worry about is if you go to a lightweight flywheel you need a different clutch disk with springs in it since the flywheel won't have springs in it like the originals do.

[mrkanda]

In a similar vein, I have a 1992 BMW 535i with stock 5spd that I just got a week ago. On the road trip back home I was definitely noticing the shorter gearing and low fuel economy (I averaged 3000-3500 rpms in 5th gear and got about 19-20mpgs over 800 miles doing between 70-75mph). I am wondering if there is any way to better this by swapping in a 6spd and/or changing my rear Diff ratio. I do plan on going turbo in the future which would help with hwy torque. Thanks, Mark

[E34GRRR]

I am wondering if there is any way to better this by swapping in a 6spd and/or changing my rear Diff ratio. I do plan on going turbo in the future which would help with hwy torque. Thanks, Mark

I don't think the 6 Speed will work but the rear differential will help

[dizzythree]

the E46 M3 had the same gearbox as well, but probably a different bellhousing too.

[TGreene]

In a similar vein, I have a 1992 BMW 535i with stock 5spd that I just got a week ago. On the road trip back home I was definitely noticing the shorter gearing and low fuel economy (I averaged 3000-3500 rpms in 5th gear and got about 19-20mpgs over 800 miles doing between 70-75mph). I am wondering if there is any way to better this by swapping in a 6spd and/or changing my rear Diff ratio. I do plan on going turbo in the future which would help with hwy torque. Thanks, Mark

Both the 5 and 6 speed transmissions have similar overdrive ratios so putting in a 6 speed gearbox will barely lower your RPMs (.81 vs .83). You would want to change your rear end ratio. The 3.23 from the M50 525i 5-speeds might be right up your alley.

[shervin]

Hello
My plan is to swap e46m3 gearbox on my 5 speed e34m5.
considering bolt holes patterns is it possible to make an adapter plate ?

[Layne]

Hello
My plan is to swap e46m3 gearbox on my 5 speed e34m5.
considering bolt holes patterns is it possible to make an adapter plate ?

Anything is possible, but it hasn't been done before so no one is going to be able to help you. It also won't be worth the cost and effort.

[demetk]

I've seen one swap where the wrong bellhousing was chopped and a right bell housing was welded into it's place.

[moroza]

A *good* welder and the right preparation - building a special jig, for starters - can make it happen. You can also buy a trashed S38 6-speed (wake me up when you find one) and swap its bellhousing with an M62 6-speed, at least if this thread is any indication.

[shervin]

Anything is possible, but it hasn't been done before so no one is going to be able to help you. It also won't be worth the cost and effort.

I think it will be very good with my 3.91 differential (in case of acceleration) so regardless of its cost and effort i'm eager yo do that.

[GazM3]

Eventually I'm going to put my e36 m3 based getrag 420g to my m635csi (same bolt pattern as the s38/s14/m30/m10). The only adaptor I have seen is to put the m20/s50/s54 box to work with the v8 and the v12. I did see samsonas have an adaptor for the 6cyl boxes to the s14 which in theory would work, but it would make the already tight installation even tighter. I'll probably do the old cut the auto bellousing with the correct bolt pattern and weld it onto the bellhoising of the 420g so it will fit into the transmission tunnel.

[shervin]

Tanks a lot
I think I should go for cutting and welding too