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M20 G/box on M50
Posted: Thu Mar 25, 2010 7:30 pm
by toecutter666
Evening all, Starting my conversion soon and trying to find out if i can use my 2.5 M20 G/box on the E34 M50 lump, have read about 318 is boxes and M20 flywheels but couldn't see anything about using the box.
Cheers
Re: M20 G/box on M50
Posted: Thu Mar 25, 2010 8:36 pm
by steviec_lj
Different mounting points as far as I can tell mate. So the answer would be no, unfortunately.
Re: M20 G/box on M50
Posted: Thu Mar 25, 2010 10:14 pm
by nickso
i think you can but the gearbox mount will need to be modded and the gearlink will need to be bent to account for the 15 or so degree difference in angle that the box sits at.
Re: M20 G/box on M50
Posted: Thu Mar 25, 2010 10:21 pm
by e21Jason
Yes it s the way to do it on e21's as the m50 goes striaght on the m20 mounts on an e21
the sump sits and an angle and on the e21 needs trimed
Jason
Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 12:00 am
by DanThe
Can you not keep the E36 mounts in an E21 Jason?
Nickso you have pm BTW
Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 6:54 am
by toecutter666
Cheers all, so is that a yes, no, maybe

, what sort of mod to the g/box mount do i need to do, has anyone got any pictures, measurements.
Thanks
Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 8:31 am
by e21Jason
The hassle of making a gearbox mount and custom linkage it's cheaper to buy a box that fits for £50-£100.
The e36 arms do not work on an e21 but the stock e21 arms bolt straight on tilt the engine over to the passenger side so you can get the manifold past the steering column.
Jason
Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 8:38 am
by blue30
I was just thinking, how to folk with the m20 boxes go on for filling the gearbox oil? Do you just jack one side of the car up to 15 degrees or what?

Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 8:51 am
by ross_jsy
it does fit.
if i get time ill whip my mount off and show you how its been modified.
then you just gotta bend the gear linkage 10 degrees and sorted
Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 4:28 pm
by nickso
toecutter666 wrote:Cheers all, so is that a yes, no, maybe

, what sort of mod to the g/box mount do i need to do, has anyone got any pictures, measurements.
Thanks
half way down.
http://www.e30zone.net/modules.php?name ... sc&start=0
Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 8:22 pm
by toecutter666
Cheers nickso, that don't look too hard to knock up, if i fit the box, i can keep my e30 prop and diff, is this correct? sorry for the dumb ass questions but i've been through most of the m50 posts and well and truly confused myself

Re: M20 G/box on M50
Posted: Fri Mar 26, 2010 8:46 pm
by baptie0
toecutter666 wrote:Cheers nickso, that don't look too hard to knock up, if i fit the box, i can keep my e30 prop and diff, is this correct? sorry for the dumb ass questions but i've been through most of the m50 posts and well and truly confused myself

correct, you can keep the original prop/diff

Re: M20 G/box on M50
Posted: Sat Mar 27, 2010 6:29 am
by toecutter666
Thanks all, thats another problem ticked off the list, the e34 donor is going for its last drive today before the big hammers are unleashed tomorrow

Re: M20 G/box on M50
Posted: Sat Mar 27, 2010 5:38 pm
by town325i
with the IS box you can keep your 325i diff and prop shaft and it sits in the correct position for the box mount no bending linkages or hammering the transmission tunnel is needed for it fit either.
Re: M20 G/box on M50
Posted: Sat Mar 27, 2010 5:49 pm
by toecutter666
Bugger it, one step forward two back

, Is there a difference between an is box and a standard one, is it just part numbers that are different or is there a physical difference.
thanks again
Darren
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 1:14 pm
by scott320i
so what engine brackets do people use for the M50/52 engine in the E30?
and what if i put a E36 box in then what Engine brackets do people use?
theres just tooo much info to try to search though!
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 1:40 pm
by bimanut
For the M50/2 engine you use the E36 mount arms with E28 M5 rubber mounts,some people use E34 2.5 rubber mounts.
If you use you E36 box i think you can use M20 gearbox mounts.
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 1:52 pm
by scott320i
E28 M5 mounts you say ! im in Australia where the M5 dont exist!
what are the differences between them? like E30/E28 M5/E36........etc
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 2:32 pm
by bimanut
The E30 mounts are too small (not strong enough)
The E28 M5 ones are lot stiffer.
Not 100% sure but i think that the E36 ones bring clearance issues they are too big as they are a lot wider.
I`ve used the E34 2.5 ones as they are the same shape as the E28 M5 ones (i think).
You can get some nice lar di dar ones from america on e bay.(at a premium $)
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 4:08 pm
by Brianmoooore
bimanut wrote:The E30 mounts are too small (not strong enough)
I have one happily running on M20 mounts! I can't see any reason why the later type with the metal cup around them isn't up to the job.
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 5:05 pm
by bimanut
I just thought that with the size of the E28 and E34 mounts the M20 ones wouldnt be up to the job.
I stand corrected, again!
I`m not sure what you mean about the metal cup part as the only ones that i have seen with metal parts in them is the E36 ones and i thought that they struggled to fit with them being a lot wider?
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 5:26 pm
by Brianmoooore
The E28 ones are stronger, but I've had no problem with M20 mounts. I was illustrating what I said in another thread, that there is no one way of doing M50 conversions, apart from sump and alloy mounts.
If you buy new M20 mounts from the dealer, they will come with a metal cup that completely surrounds the rubber. This is a recent development, and shows that BMW is still developing the E30!
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 5:33 pm
by Rav335uk
Brianmoooore wrote:
If you buy new M20 mounts from the dealer, they will come with a metal cup that completely surrounds the rubber. This is a recent development, and shows that BMW is still developing the E30!
Sorrt Brian, don't think it's recent, I have metal cups surrounding my rubber mounts and my cars a 1990.

Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 6:07 pm
by town325i
Rav335uk wrote:Brianmoooore wrote:
If you buy new M20 mounts from the dealer, they will come with a metal cup that completely surrounds the rubber. This is a recent development, and shows that BMW is still developing the E30!
Sorrt Brian, don't think it's recent, I have metal cups surrounding my rubber mounts and my cars a 1990.

It must be i bought M20 rubber engine mounts 2 years ago and they are the same as all the ones ive seen bare rubber. These are genuine ones too not cheap tat from GSF.
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 6:16 pm
by Rav335uk
Mine have been on since the day I bought the car.

Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 6:23 pm
by toecutter666
Thats all very nice but does any one have an answer to my 1.8 g/box question?

Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 8:07 pm
by E30BeemerLad
I believe Daimlerman used a M40 gearbox on his M50 swap, bolts straight up using M20 flywheel & clutch and 325 prop
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 10:53 pm
by ross_jsy
so the m20 mounts wiill actually work? i thought they needed spacing of some sort?
could possibly save me the $200 that the akg ones cost since my m20 was siting on some poly bushes which I am sure are up to the job.
Re: M20 G/box on M50
Posted: Sun Mar 28, 2010 11:55 pm
by DanThe
How tall are they Ross? I know the AKG ones are shorter than the mounts that are normally used.
The AKG mounts are made with the correct angle though
Re: M20 G/box on M50
Posted: Mon Mar 29, 2010 5:23 pm
by ross_jsy
just measured them, the poly part is 40mm thick.
if i can get away with using them for now it would be good as can free up a bit of ££ which is getting tight now!
Re: M20 G/box on M50
Posted: Mon Mar 29, 2010 5:49 pm
by DanThe
Well the 5 series type mounts which are normally used are about 75mm tall, you will be very close to the steering rack, on Bobs old car the E36 rack was mounted in the high position and it was contacting the sump, there is only about 15mm difference between the low position and the high position
This was with E34 type mounts also
Re: M20 G/box on M50
Posted: Mon Mar 29, 2010 5:57 pm
by ross_jsy
hmm might aswell just get in the garage and have a go

Re: M20 G/box on M50
Posted: Tue Mar 30, 2010 8:35 pm
by ross_jsy
far too short by the looks of things, ill just hold out for the akg's