6MT to 5MT swap

Right now, trying to decide on what to do with my track car. I've heard of people swapping in a non-M 5MT to save weight. AND...I like the fact that replacement units and consumables seem to be cheaper and plentiful.

I think the hydraulics are the same and everything bolts up except for the driveshaft.

Anyone have some more info? I did search and couldn't find anything.

This would be sick. I think you'll find better help on m3forum.net

I think I remember seeing someone use an e36 M 5speed tranny. I could be wrong though.

Originally Posted by ANREC330

I think I remember seeing someone use an e36 M 5speed tranny. I could be wrong though.

That's the same as the e46 non m 5 speed trans

I guess the only big question is the driveshaft. I'd like to see if an OE part fits before I go custom.

Ive definitely heard of it being done, so it's very possible. The 5 speeds are more durable as well

Originally Posted by bigjae1976

I guess the only big question is the driveshaft. I'd like to see if an OE part fits before I go custom.

Maybe a 330i driveshaft -- depends on whether or not the E46 M3 diff is longer

I know the M3 diff is 40mm closer to the front of the car vs a non-M.

Driveshaft lengths from realOEM

330 5Sp 1550mm
M3 1404mm

So the M3 6MT is 146mm shorter, 40mm of that being the difference in diff location. Which means the 6SP tranny (looks like M and non-M 6MT gearboxes are the same length) 106mm closer to the rear of the car.

So I would need a 1510mm long driveshaft assuming the center bearing is in the same location.

Other lengths...
330 auto 1403mm
330 6Sp 1444mm
330 GM5 1358mm

Basically I guess my only choice is to buy a 5MT driveshaft and shorten the rear portion by 40mm?

The major hydraulic pieces are the same except for the hard line from the rubber hose to the slave and the bracket. The input shaft bearing, flywheel bolts, dowel pin are the same part #'s.

The only other differences in part numbers is the clutch disc, pressure plate, throwout bearing, and flywheel.

So this is my theory. I keep the M3 hydraulics. I swap the flywheel, pressure plate, clutch disc and throwout bearing. Swap shifters. Bolt up the trans and then install a custom driveshaft with the rear portion shortened by 40mm.

The getrag 420g (M3) is supposed to be 23.5 lbs heavier than the ZF320.

Yeah...found the answer here...

http://forums.bimmerforums.com/forum...-swap-question

When I read the title my first thought was, why the heck would you do that. Makes sense now. Good luck. Smart move!!

23 pounds isn't that great of an amount to save, why not do 4.10 LSD instead?

I could do both!

yeah, that would definitely be a screamer if you did. Are you going to drive the car to the track or do you trailer?

If you did 4.10's with a 5speed your max speed would be around 145 mph in 5th redlined

Bimmerworld can source you the correct driveshaft, I think it's about $600. You can also save a ton of weight off the 6 speed clutch and flywheel, in the realm of 25lbs. You'll also need a different trans cross brace, I'm pretty sure(99%) it's one from a non-M E46 5 speed.

I think most are using US spec E36 M3 5sp with the ZF320 box. Which I think is also used o. The E46 330.

I would trailer if I were doing the 4.10 and 5sp.

I'm all in for saving weight, but the getrag feels so much nicer. I keep hearing the 5 spd is stronger, but I'd like to see what the values are for both.

You could always do a carbon drive shaft to save weight