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gearbox for M50

Posted: Fri May 14, 2010 2:29 pm
by stup86
Until yesterday I was going to use the ZF gearbox that came with my M50 engine.

I then heard about the weight difference between the M50 dual mass flywheel and the E30 M20 flywheel.

So now, I'm looking at using the M20 gearbox, starter and flywheel.

BUT...

What parts do I now need? I have the gear linkage from an E36 325i that i guess is now redundant??

I was going to buy an E36 328i prop too, but i guess this too is now not required.

What prop do I need and also what about the engine mounts?

Do they stay the same or does the engine need to be at a different angle (i remember hearing something about the engine being sat at 7 degrees or something!?!?!?!) - I think I remember on here someone saying that an E28 M5 mount on one side with an E30 M20 mount on the other will put the engine at the right angle - can someone confirm.

Also if anyone has a M20 gearbox, flywheel and starter then let me know.

Cheers

Stu

Re: gearbox for M50

Posted: Fri May 14, 2010 2:42 pm
by bimanut
I cant comment on the use of different mounts but when people have used M20 boxes they have twisted the cradel a bit to compensate for the different angle i assume you would have to do the same to the selector rod.

I would have thought you would use the E30 325 prop with the M20 box because i think the M20 boxes are a bit longer than the M40 ones .I`m using the M40 box and a 320 prop,the 325 one is used the centre bearing didnt line up.

Re: gearbox for M50

Posted: Fri May 14, 2010 2:56 pm
by E30BeemerLad
Forget the M20 gearbox, hassle with the angle it sits and and the gerarbox mount needs modifying and the shifter bending etc.

Use either the gearbox from a 318is or even the 318i gearbox - Getrag 240, use the M20 flywheel, starter & clutch, 320 gear shifter mechanism and 325 propshaft.

All bolts straight in without any nodifications whatsoever and the gearbox is man enough for the job

Re: gearbox for M50

Posted: Fri May 14, 2010 2:57 pm
by stup86
I have a 318i gearbox in the garage right now. Is that definately man enough?

Re: gearbox for M50

Posted: Fri May 14, 2010 3:04 pm
by E30BeemerLad
Daimlerman has used the M40 gearbox on his M50 touring and has no problems, i'm using the M42 gearbox (of which I think there are very little physical differences at all) and I've done 20+ 1/4 mile passes with it and gave it death everywhere without issues on a more powerful M52 engine.

I'd have no qualms about using the box mate

Re: gearbox for M50

Posted: Fri May 14, 2010 4:45 pm
by jmc330i
E30BeemerLad wrote:Daimlerman has used the M40 gearbox on his M50 touring and has no problems, i'm using the M42 gearbox (of which I think there are very little physical differences at all)
I think the bellhousing is a slightly different shape between to the 2, but Ive not had both side by side to compare.
I'd have no qualms about using the box mate
Thats good news 8) winkeye

Re: gearbox for M50

Posted: Fri May 14, 2010 11:39 pm
by Brianmoooore
stup86 wrote:Until yesterday I was going to use the ZF gearbox that came with my M50 engine.

I then heard about the weight difference between the M50 dual mass flywheel and the E30 M20 flywheel.
What's using a M20 flywheel instead of an M50 one got to do with changing the gearbox?

Re: gearbox for M50

Posted: Sat May 15, 2010 7:51 am
by stup86
Didn't know i could do that!

So I can just change the flywheel, starter and clutch and use my ZF box?

Re: gearbox for M50

Posted: Sat May 15, 2010 9:53 am
by Brianmoooore
I have one running OK with the standard release bearing - built before I joined the zone. Probably some less than ideal angles in there, but it works.

Re: gearbox for M50

Posted: Sat May 15, 2010 1:11 pm
by DanThe
Ive never had a problem with standard M20 bearings before either.

Here is a modded bearing I made yesterday, for a different gearbox

Image

Re: gearbox for M50

Posted: Sat May 15, 2010 1:13 pm
by Cook318IS
willnz wrote:Yes, all you need to do is raise the height of the clutch fork bearing pads
I'm wondering if this will sort my problem out... Whats the reason behind doing this will?

Re: gearbox for M50

Posted: Sat May 15, 2010 1:15 pm
by DanThe
I think it will make it worse mate, your problem is getting better with less throw, so you dont want any more

Re: gearbox for M50

Posted: Sat May 15, 2010 1:18 pm
by Cook318IS
thats true :o: - thanks again dan :D I forked out for another clutch today too :cry:

Anyway OT! i much prefer the feel of my zf box over the m40 box i used to have. Although if you do use the zf box - change the clutch slave cylinder before you fit it! Trust me on this...

Re: gearbox for M50

Posted: Sat May 15, 2010 1:36 pm
by DanThe
I thought you had fitted a new clutch already? Dont forget pics of the old one :wink:

Re: gearbox for M50

Posted: Sat May 15, 2010 1:38 pm
by Cook318IS
DanThe wrote:I thought you had fitted a new clutch already? Dont forget pics of the old one :wink:
I have, its barely got 4k miles on it. But iirc... its an LUK one :? I thought well everything else is brand new and ive got this problem and the gearbox is coming out again... fuck it i'll fork out for a brand spankers sachs clutch :cry: