Easy question 4 the M50 coverters

[stevetigger]

I might just ring BMW tomorrow, it might be an old part number now! They will tell me what gearbox it is!

[Widge]

Wouldn't be so sure, they were about as much use as a chocolate fire guard when I went in to get some widgets for the rear head rests today.

[pete1979]

need to get yourself down the brakers and get a prop and output flange from a 320 or 325 be its about 36mm fit straght on job done

[Brianmoooore]

Been checking the various engines and boxes around my workshop this morning, so heres my 10p's worth to add even more confusion.

A ZF box from a 93 E34 525 has a ~96mm dia. output flange with 12mm bolts. The reverse light switch is on the right hand side.

A Getrag box from a (£60) 93 E36 525 has an output flange of ~80mm (same as E30) but has 12mm bolts. The reverse light switch is on the left hand side.

A 2000 E39 525 has a ~96mm flange and 12mm bolts.

A M40 and a M20B25 box both have an outpiut flange diameter of ~80mm, but with 10mm bolts.

The output shafts associated with the diffenent size flanges appear to be of a different diameter so I don't think they can be swapped. Haven't actually tried it).

Now, to add further confusion, the box in my M50 conversion is from a 92 non-vanos E36 320, which I can't get at to give details at the moment.
Before I fitted it, it was sde by side on the floor with the 93 E34 525 box, and I thought they were virtually identical, BUT, I used a standard E30 325 prop, so it must have the smaller flange. I'm also pretty sure the reverse light switch is on the right.
I may or may not have 10mm bolts in 12mm holes. Didn't notice anything amiss when I fitted the prop, but back then I wasn't aware there was two different sizes. I shall be checking when the ramp is free!

[stevetigger]

Cheers Brian, So what box do you think I have??

[DanThe]

I may or may not have 10mm bolts in 12mm holes. Didn't notice anything amiss when I fitted the prop, but back then I wasn't aware there was two different sizes. I shall be checking when the ramp is free!

Now that you mention it

The reverse light switch on my E36 525 Gettrag is on the LHD side

[Brianmoooore]

Cheers Brian, So what box do you think I have??

No idea! I don't even know what's in mine now!! But I'm going to check those bolt sizes pretty soon.

[stevetigger]

Cheers Brian, So what box do you think I have??

No idea! I don't even know what's in mine now!! But I'm going to check those bolt sizes pretty soon.

Cool, So now I've started you off on this one! Soon I will have the whole zone wondering what gearbox they have in there M50's

[jmc330i]

the box in my M50 conversion is from a 92 non-vanos E36 320, Before I fitted it, it was sde by side on the floor with the 93 E34 525 box, and I thought they were virtually identical, BUT, I used a standard E30 325 prop

From what Ive seen, that would be right (not sure about bolt sizes). It seems some M50 E34s had the smaller flange and some had the larger, but I cant make out what would be the differing factors between the E34s with the smaller or larger one

My ETK suggests that E34s upto the 9/95 had the smaller flange, common with the E36 320i/325i (able to take the E30 325i prop) and those late ones built after 9/95 had the larger thats common with the 328i etc (needing the E30 M3 prop).

Im beginning to think we will never know - Ive been all over my E30 325i box and cant find much to ID that

[Brianmoooore]

My ETK suggests that E34s upto the 9/95 had the smaller flange, common with the E36 320i/325i (able to take the E30 325i prop) and those late ones built after 9/95 had the larger thats common with the 328i etc (needing the E30 M3 prop).

Doesn't fit with what I have. 93 E34 525 definitely has the large flange.
I also stuck a non vanos M50B25 and box from a 92 E34 back into the car which this engine came out of, and that coupled up to the prop with no problem, so the 93 E34 525 must have the large flange as well.

[jmc330i]

E34 325

E34 325???

When I say 'large flange' Im mean one thats the same size as the E30 M3/E36 M3. The E30 325i prop will not fit those because the E30 325i flange is smaller.

Sorry, I forgot to say in my above post, that the ETK also lists the larger flange in E34 models from 1990 to 1995 as well as what I said about pre 9/95 and post 9/95 - thats why I couldnt see what differing factors there are.

[stevetigger]

So tomorrow when out doing more to my car, I need to measure the distance between the holes on the Gearbox?? My 318i prop was far to small but are the 325i prop the same size?? If not then an E30 325i prop might fit?? Its getting very confusing now!

[jmc330i]

The E30 318i and 325i props are different, but the important bit is the bolt hole spacing. This should be the same between 318i and 325i.

As luck would have it, I now have an E30 M3 prop (fitted to my Sport), an E30 325i prop (in the garage) and an E30 318i prop (fitted to my newly acquired 318i ).

When I get home from work tomorrow morning, I will measure the bolt holes of the 318i and 325i props to see if they are the same - I know for a fact the E30 M3 one is bigger than the 325i.

[Brianmoooore]

E34 325

E34 325???.

E34 325? Where do you see that?
So what's the conclusions then? E34 M50s have always had the larger flange, and less than 2.8 E36s have the smaller one?
Still remains the question of the 10mm and 12mm bolts though.

[stevetigger]

The E30 318i and 325i props are different, but the important bit is the bolt hole spacing. This should be the same between 318i and 325i.

As luck would have it, I now have an E30 M3 prop (fitted to my Sport), an E30 325i prop (in the garage) and an E30 318i prop (fitted to my newly acquired 318i ).

When I get home from work tomorrow morning, I will measure the bolt holes of the 318i and 325i props to see if they are the same - I know for a fact the E30 M3 one is bigger than the 325i.

That would be a great help, I dont care what gearbox I have as long as I buy the right propshaft!

[Brianmoooore]

Gearbox ends of an E30 325 and an E30 318 prop are the same - smaller flange, with 10mm holes. I have one each of those in my workshop.

[stevetigger]

So that deffo means I need the E30 M3 prop!

[jmc330i]

E34 325

E34 325???.

E34 325? Where do you see that?

So what's the conclusions then? E34 M50s have always had the larger flange, and less than 2.8 E36s have the smaller one?
Still remains the question of the 10mm and 12mm bolts though.

It seems the E34 had both The E36 328i has the larger and the rest of the E36 6cyls had the smaller.

Whilst writing this Ive been looking at the ETK and might have found where the confusion is coming from. The ETK says that although all of the E36 328i has the larger output flange, so do some of the 325i and 323i's. This confused the hell out of me, but after search round the ETK the difference is down to whether its a coupe or 4dr.

Now I know this doesnt help with the E34 - 4dr or touring only, but it could explain why Im seeing both the smaller and larger output flange listed for the E34. I dont have time to check that out now, because I must go to work, but give me a couple days and I will see what I can find - I have to sort this out if only for myself


Steve - No problems mate, will post up the sizes in the morning, berfore 10am most likely.

EDIT - Brian beat me to it.

[stevetigger]

Its crazy all the differences!

So we are still no closer to finding out what box I have?

Or can you tell from the photo I put up?

[jmc330i]

Sorry mate, I tried to reply last night but got the bandwidth limit error.

Yes, I would 100% say you need the E30 M3 prop.

And no, still not any closer to finding out what gearbox you have

[pete1979]

just done a m50 into an e30 had a 36 and a 34 box both the same iv got an early 34 box that also has the big flange i used a e30 325 output flange bolted straight up so i have e36 m50 and box e30 325 output flange and prop with a e30 diff case with a e34 lsd in it hope this helps
any problems give me a ring 07944133875

[DanThe]

any pics of the diff swap mate?

[Laimis]

I am doing M50 swap for my friend now, and i have propshaft problems too. E30 325i propshaft lenght is correct, but flex disc (guibo) is small. And my E34 525iX gearbox flange is big.
I see few ways how to solve this.
1) late 325e or 324td propshaft. It is almost same lenght as e30 325i and with big flange and flex disc. I will try this tomorrow.
2) Custom propshaft. e30+e34. Expensive.
3) Custom flex disc (for small and big flange). I know who can make one, but not sure about price.
4) Change gearbox flange to smaller one from M50 2.0 box and re-use e30 325i propshaft.

From pic in this thread i can guess that you got ZF transmission, because i have the same.

Hope this helps.
Sorry for my bad english.

[DanThe]

If I came to the above problem, I would swap/part-ex the gearbox for the one with the correct flange. At the end of the day its going to cost a lot less than the prop from an M3 or a custom made one.
Unless the box has 6 gears of course

[Laimis]

324td propshaft came in perfectly, even without any lenght corrections.

[stevetigger]

324td propshaft came in perfectly, even without any lenght corrections.

More rare than the E30 M3 prop because we didn't get the 324td in this country.