M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: visionracingdevelopments on October 06, 2009, 04:04:45 AM

Title: Swapping gearbox flanges
Post by: visionracingdevelopments on October 06, 2009, 04:04:45 AM

I have a prop shaft dialema and I'm wondering if the outout flanges on the getrag gearboxes can be swapped without taking the gearbox apart?

Here is the back of the 'M42' box:

(http://i296.photobucket.com/albums/mm184/rix313/IMG_5303.jpg)


Here is the back of the 'M40' box:

(http://i296.photobucket.com/albums/mm184/rix313/IMG_5306.jpg)


I have an M40 box fitted but need the M42 flange.

Title: Swapping gearbox flanges
Post by: Xtremelylow on October 06, 2009, 07:24:49 AM

not 100% sure if its the same but I swapped my m42 flange to a m3 tranny for my 318 turbo and it worked out ok. had to shave the m3 nut some and had to make a spacer for it but that was it.

Title: Swapping gearbox flanges
Post by: Xtremelylow on October 06, 2009, 07:25:27 AM

oh ya and also no you dont have to take apart the tranny just take off the nut and use a puller on it

Title: Swapping gearbox flanges
Post by: visionracingdevelopments on October 06, 2009, 08:42:03 AM

No one on this earth can tell me what prop shaft I need, my iS one is too short for the M40 box (for obvious reasons pictured) so wanted to see if the flanges can be changed without pulling it apart.

Can you just explain what set up you have?

Title: Swapping gearbox flanges
Post by: DesktopDave on October 06, 2009, 10:03:50 AM

I'd figure the easiest solution is to grab an M40 drive shaft as well if you don't want to muck with the output flange.  The flanges are the same pattern, right?

There is some adjustability to the two part shafts, but that looks too far to loosen the nut & stretch.

Title: Swapping gearbox flanges
Post by: visionracingdevelopments on October 06, 2009, 10:49:00 AM

The M40 shaft is even shorter than the M42 one:

(http://i296.photobucket.com/albums/mm184/rix313/IMG_5313.jpg)

The adjustment on the shaft is the diff side of the center bearing. If I move the whole lot closer to the box it bearing is no where near the stud holes for it to bolt to.

Title: Swapping gearbox flanges
Post by: DesktopDave on October 06, 2009, 12:03:07 PM

Wow!  I'm stumped...I thought the M40 block was the same, so a different transmission would just need the proper drive shaft to fit.  The diff noses are all in the same place...

Maybe get it extended?  It's pricey 'round here (easily available though) but sometimes that's the only way.