Author Topic: Transmission Options (Read 11365 times)

SonomaGTLN2 · « **on:** June 15, 2007, 08:38:33 PM »

Hello everyone,

As some of you may know I am planning to do an M42 swap into my E21 in the near future. I was wondering what the manual transmissions the M42 E30's and E36's use. I believe my current transmission with the M10 is the Getrag 245 (it is a 5 speed). I have heard that the Getrag 240 was used on M42. Does anyone know how these two stack up dimensionally? In other words, would my current transmission on the M10 be compatible with the M42?

Thanks a bunch,
AJ

..I'll probably just end up buying a wrecked M42 powered car and use everything off of that, but I guess I'd like to have a backup plan for transmissions.

Abrax · « **Reply #1 on:** June 16, 2007, 12:48:14 PM »

Definately not... You have different mounting points in the M42 tranny case.

Frankie · « **Reply #2 on:** June 16, 2007, 01:12:27 PM »

E34 518i has the same tranny

Abrax · « **Reply #3 on:** June 16, 2007, 03:31:47 PM »

Disagreed - E34 518i has M40 engine which has same as M42 mounts... Still different than M10... No way to fit it there

Abrax · « **Reply #4 on:** June 16, 2007, 03:32:57 PM »

Why not to swap tranny too?

kowalski · « **Reply #5 on:** June 16, 2007, 04:12:30 PM »

is there any 6 speeds that will bolt up to the m42 with just bellhousing mods?

Frankie · « **Reply #6 on:** June 17, 2007, 12:17:25 AM »

Quote from: Abrax;27839

Disagreed - E34 518i has M40 engine which has same as M42 mounts... Still different than M10... No way to fit it there

Well, ETK indicates that same tranny is in 518 M40 engine.

johna · « **Reply #7 on:** June 17, 2007, 01:01:57 AM »

Quote from: kowalski;27854

is there any 6 speeds that will bolt up to the m42 with just bellhousing mods?

I think the Euro E36 M3 6-speed will fit fairly easily. Someone on here has one on an M42 E36 (gizmo318).

kowalski · « **Reply #8 on:** June 17, 2007, 05:19:01 AM »

Quote from: john318isau;27870

I think the Euro E36 M3 6-speed will fit fairly easily. Someone on here has one on an M42 E36 (gizmo318).

Damn this euro spec, why couldn't we get 6 speeds in the us spec m3's...

bar73k · « **Reply #9 on:** June 17, 2007, 08:12:13 AM »

To my knowledge the following gearboxes will bolt up to an M42

m40 gearboxes getrag 240(e30 318i (1988 and on))
m42 gearboxes getrag 240 (all e30/e36 interchangeable)
m43 gearboxes getrag 220 (e36 316i) 100% <-- had one in my car recently till i blew my clutch
m44 gearboxes (e36 318i) 100%

m20 gearboxes will bolt up (but i am slightly confused here)
i have a getrag 260 from a 323i and it looks like it will be a direct fit
i only need to put an older style shifter in. i will be test fitting the
gearbox tomorrow.
i have been told that they do not fit and that they only bolt up using
the 4 main bolts, and when they do they sit at too much of an angle
so its not possible.
it maybe a case that some m20 model gearboxes fit some don't

m50 gearboxes will
m52 gearboxes will
s50 gearboxes will
s52 geatboxes will

not 100% sure about the above four but pretty damn sure

one thing to remember is that e30 gearboxes have a fifth gear overdrive ratio
and e36 gearboxes do not (e36 5th gear = 1:1).
so if switching from a e30 gearbox to a e36 gearbox you would need to
change your differential to bring the drive line ratios back to standard.

pretty much im confident that any 4 cylinder gearbox (in the e30/e36 range)
made after 1988 will bolt up to an m42

an m10 gearbox will 100% Not bolt up to a m42

rob_e30 · « **Reply #10 on:** June 17, 2007, 12:02:52 PM »

I've attached a Getrag 260 to a M42 in an E30. The tranny does rotate over farther and only the 4 main bolts line up. It's also a different length meaning you need to modify the tranny brace, the perhaps change the length of the shifter linkage as well as the angle of the shear selector rod (to get the shifter into the cockpit through the proper hole), the prop shaft will also be the incorrect length. Take a lot of measurements and you cannot assume that the rear of the engine will be in the same place in the car as the old engine.

If you leave the entire drive line in place with the new engine there is no guaranty that the motor mounts will line up or that the tranny won't need to be rotated 10-15 degrees.

Abrax · « **Reply #11 on:** June 18, 2007, 12:03:59 AM »

Bar73K - great info i can confirm almost /i simply don't know much about M/S 50/52/ all

I've succesfully installed getrag 225 from cecotto M3 - it needed really tuff changes, but works great and feels just fenomenous...

After few months of driving, the next time I will change tranny I will use 6 speed E36 M3 tranny...

Almost everything is possible - just get the proper idea of how to do it...

SonomaGTLN2 · « **Reply #12 on:** June 18, 2007, 07:09:20 PM »

Thanks for the replies guys, I'll probably just keep my eyes out for a wrecked car with complete driveline. The reason I asked is because I could get my hands on a good trans for my M10 (my current one is in rough shape) and figured if I could use it on the M42 I would just go ahead and get it. I'll just ride it out with the original one for now then get a complete set when I get the motor.

Thanks again,
AJ