E34 diff

[toecutter666]

I'm starting to put together the parts i need to do a m50 conversion, what ratio diff will i need or can i put the e34 internals in the e30 case, sorry if it's a stupid question. Cheers

[alync205]

I am fairly sure that you can fit a E34 diff to a E30 by puttin the E30 backplate onto the E34 diff.

[S38B38]

I'm starting to put together the parts i need to do a m50 conversion, what ratio diff will i need or can i put the e34 internals in the e30 case, sorry if it's a stupid question. Cheers

I am fairly sure that you can fit a E34 diff to a E30 by puttin the E30 backplate onto the E34 diff.

The small diff of e34 hafe the same casing as 325 E30 ,, 210

M50 used 1:1 in fifth gear on their 5 speed gearbox ,, so 3.23 was the diff for sedan and 3.38 for touring



try to get the 518 diff ,, that is 3.46 and you just have to replace replace the lid/backplate LSD would be a must imo

[toecutter666]

Ok thanks guys, would my 525 have a small diff or did they only come on the 518?

[town325i]

its the E28 diff that fits straight to an E30 not E34 diff on the front of rebuilding the e34 diff into e30 diff i do not no.

[toecutter666]

Thanks town, will have to go on the hunt for some diffs then

[Dezzy]

For the M50 you can use anything from 2.94-3.25

I am using 3.15 as that's about the best IMO

[town325i]

For the M50 you can use anything from 2.94-3.25

I am using 3.15 as that's about the best IMO

This is if your using an M50 gearbox

[Dezzy]

For the M50 you can use anything from 2.94-3.25

I am using 3.15 as that's about the best IMO

This is if your using an M50 gearbox

Yes.

[toecutter666]

Was planning on using both engine and box from the e34, what model am i looking for to get the 3.15 ratio diff? sorry for all the dumb questions but this is all new to me

[Dezzy]

Was planning on using both engine and box from the e34, what model am i looking for to get the 3.15 ratio diff? sorry for all the dumb questions but this is all new to me

E36/34 same box 3.15 diff will be a nice choice IMO. If you can find one a z3m has this ratio, will bolt straight on and has cooling fins in the back plate which is

[Andyboy]

E30's never used a 210 diff - that's the big mutha from the E23, E32. 635CSi. M535i etc. E30's use either the small case 168 or the 188 (323i, 325i and M3).
The only E34 to use the E30 188 casing (four 19mm bolts on top) is either a 518i or a 520i and possibly a 524td. Everything else uses the E32 type diff with the different mountings. A 24v 520i diff has a

The best diff for an M50 conversion is an E28 525e 3.07. Fit the E30 325i output shafts and rear cover and away you go. A 3.45 from an E34 would be fine with just the rear cover swapped. These used E30 output shafts.

E36 Compact diffs do NOT fit an E30. They will physically bolt into the E30 axle beam but the diff output shafts are the wrong diameter, 80mm rather than the E30 86mm. You cannot fit E30 output shafts into a Compact diff because they use an E36 differential unit and the output shaft circlips are in the wrong place.

[toecutter666]

Cheers andy boy, what are the chances of picking up an e28 3.07? Are these rocking horse poo or dime a dozen?

[Andyboy]

I've thrown them away in the past. Last one I had I sold for £50. Ask on www.bmw5.co.uk

[toecutter666]

Will do, thanks for the link.

[vokietis]

can get e34 3.15 ratio diff,will need to use your own back plate.£100