Large 210mm Diff into E30...

[[RX3]]

I have been looking at possibly buying a large 210mm differential to put into my e30.

Would anyone know what modifications are required for it to fit? Has anyone done this before?

Cheers...

[BMWTurbo]

A crane would be handy

From what I know there isn't a output flange that fits in to the the large case diff to suit the E30 stlye CV's so you'll need to step up to the E32 etc style CV's. which bolt on to the TA and Diff sides. The problem I've found and I suspect will be even more pronounced with e30 TA's etc is that the half shafts are too long. I'm looknig at custom half shafts to fit the, diff, not even looking at mounting it etc.

The diff is a monster, I haven't looked in to the alignment and tailshaft requirements yet, but they'll need working on as well as new structure to support the rear of the diff and back to the body etc.

In short, not a simple job, but please resolve the issues and post back

[[RX3]]

I might be onto something with the E28...

[BMWTurbo]

I might be onto something with the E28...

E28 rear end will fit with 13mm(I think) offset bushes in the subframe. You'll need to convert to true coil overs on the rear as the TA's don't have spring pads... You do get the bolt on style cv, but they are the smaller type.... E32 flanges should boot in to suit the larger cv's though...

You won't be able to bolt the large case in though...

[[RX3]]

I found this on e30tech. I wish I could ask the owner of the TTV12 E30 what he ended up with but my registration isn't activated yet...

After some digging I found out that E31 propshaft is very short - just 1322 mm. Do you remember how far are original mounts for propshaft bearing from the guibo (Hardyscheibe)? As I understand you just changed rear joint on shaft?

After some digging about 210 diff I can say that without custom job it will be hard to solve.
Generals:
1. E28 diff have the same mounting on main case (on the cover it needs custom bracket to connect with E30 mounting)
2. PCD (LK) bolts on output flange is 94 mm, the same as 850iA and M3 Z
3. PCD in 850i and CSi is 102 mm
4. The flanges in 850iA are THE SAME as in E28 (you can swap them)
5. The halfshaft diameter in 850iA is the same as in Z3 M but in 850i and CSi is bigger - 33 mm
6. The 850i/CSi outer CV joint can be fitted in Z3 M hub
So IF 210 diff is not too much wider than 188 it shoud be possible to use Z3 M halfshafts. But BMW used bigger shafts and CV joints in 850i/CSi not without reasons. Most probably they found out that with normal clutch and hard gearchanges the 850iA halfschafts are not enough strong. I know that E30 is lighter over 500 kg than E31 but I'm going to modyfy my engine.
As far as we don't know the difference between 188 and 210 it is hard to say can Z3 M shafts can be used with smaller shafts.
Lots of quarry, I know, but as I wrote before: good research is a base of success. I know it from my experience.
Jan
EDIT:
There is something with the strengh of the transmision because I found that in B10 BiTurbo Alpina (IIRC 490 Nm of torque) used big guibo from 850i.

[BMWTurbo]

Good info sounds about right... The 210mm diff is about 2Xmm wider than a 188 diff. I've got the actuals in my thread... ZM half shaft size would be very good to know as e32 stuff is too long.

I am going to sort out the large half shafts with the 188 diff for starters, but make sure I can retro the 210 if I need to...

[morerevsm3]

Andraes from www.pure_pf.com has a 210mm diff in his S38T powered E30 M3, he generally doesn't mind sharing information

[[RX3]]

From where? That link doesn't bring anything up...

[morerevsm3]

http://pure-pf.com/wp_new/

[BMWTurbo]

Has PPF changed it Alan? Kilander and PFF both are listed as '535' rear ends in Performance BMW. This is essentially a med case 188mm diff from the E28's with an E30 rear cover on it. I have that already fitted, but al targeting easy integration of the large (210mm) diff if/when I break the 188...

[morerevsm3]

Andreas posted on bimmerforums that he had an M5 diff in it, which is 210mm, was a couple of years ago though, so my memory may be incorrect?

[BMWTurbo]

Andreas posted on bimmerforums that he had an M5 diff in it, which is 210mm, was a couple of years ago though, so my memory may be incorrect?

Ahh yeah, pretty cerain an 'm5' diff from an E28 is the same as the '535' diff which is a 188mm med case diff They are still top mount diffs, hence bolt in to the E28 subframe.

This is an Aussie E28 M5 diff with the E30 style back cover on it. I was sizing up the larger E32 CV/halftshafts. The E32's 735's use a med case (188mm) with the larger halfshafts, so the output flanges can be used in the med case diff to get the larger CV's adapated. The E32 inner TA flanges swap over with the E28 arms also to get teh right sized flange there, just need to resolve the halfshafts being too long from the 32's.


This is an E28/E30 size smaller CV TA inner flange compared to the larger E32 style.

[morerevsm3]

my M3 is medium case with larger flanges as well, I am pretty sure Andreas has E34 M5 rear end though, which is 210mm

found it
http://forums.bimmerforums.com/forum...=421915&page=3

[BMWTurbo]

He must have changed it or fed PBMW the wrong info, the dark green one with plates 'PPF001' lists '...E36 M3 front brakes, E28 M535i rear brakes , E28 M535i rear axle' This was back in '04 so things could very well have changed.

I'll do some more looking as I know I've see a rear end photo of either Andreas' or Kilanders (pretty sure it was Kilanders) with a custom rear crossmember and med case diff. Might have been in Zoom actually.

Interesting, but not definitive... Seems they reference the E34 and E28 as the same O/S...

http://www.e30tech.com/forum/showthread.php?t=112390
http://ww.e30tech.com/forum/showthread.php?p=1029750
http://www.e30tech.com/forum/showthread.php?t=102331

Could always do this

PFF List E34 M5 rear end.

[Gruelius]

lol @ r3vlimited typical responses... shame that e30tech isnt administered anymore...

Someone put in a whole e24 rear end just for 5lug, if you ask me thatd probs be the way to go, plus you get a nice excuse for widebody.. ill try find the thread.

[morerevsm3]

E24 is only 188mm, won't hold 800+ hp

[Jason Broadhurst]

I had an e28, e30 med and an m3 med diff and bar the rear diff cover plate they are all identical internally and strength wise I think. From what I remember a E36 also has the small 6 bold diff and med 8 bolt diff identical to the E30.

http://dairally.net/e30/ My old website which the domain isn't registered anymore. It has some info on there.

[morerevsm3]

late E24, E28, E30 6cyl (except 320i and half the 323is) and E36ti all have same diff except back plate, E36, E34 6 cylinders also have 188mm crownwheel, but different housings

[[RX3]]

yep, nearly impossible to get good info on that r3v forum so i have given up on that. i just like the idea of trying to work something out now rather than when / if the centre gets damaged. i would rather sell it now in a working condition and put the money towards the large centre and have piece of mind knowing that it was the strongest option...

[BMWTurbo]

Hrrrrmm farkin... You now have me wanting to go straight to the 3.15 LSD rather then mucking around with the med case. I have to change my rear diff mount height due to NOLTEC anyways.

RX3 are you aware of the limited ratios in large case diff's? I know of 3.15's which is all Aust delivered 7-series LSD's. and I recently sourced and poured many $'s in to a 3.64 large case gearset from the US, that I had fitted to my spare 3.15 LSD.

[[RX3]]

yes i know. my current lsd is 2.79. i would like to use a 2.81

3 speed auto...

[BMWTurbo]

Not sure if you have progressed with this. With some time on my hands tonight I had a look at it and it might not be as difficult as I had thought.
Large case left, med case right.




I reckon with some cutting and welding the E32/34 style bracket will mate with the E28/30 stye top mount bracket and with a new mostache bar on the rear of the large case might even go somewhere near the E30 rear pick up. Obviously you piss the std E30 sheet bracket for the rear diff and double up with another on the RHS also to give it some chance of holding together. Looks like some reliefe might be needed for the top to not foul the e30 crossmember, and teh large case will sit about 12mm lower then the med case, but not of huge concern.

Lastly custom TS and half shaft's will be needed, but can retain the BMW large CV's (which are the same PCD, OD and spline as Porsche 930 ones).

[JZK25]

It didn't appear to be too difficult to fit an R200 to the rear of an E30. I chucked one up in there and dodgily bolted it up. Dunno about sub 3.00 ratio's though.

[[RX3]]

wont bother with it anymore. i will just keep the medium case for the moment then save up for something big like a ford 9' that has plenty of options. will be a cunt of a job but at least i can then take the car down the strip with a bit more confidence knowing that the rear end isn't going to let go on me.

JZK, th400 remember, would hate to be cruising around doing 4,000rpm at 100kmh like the liberty for example.

[BMWTurbo]

Not the pretiest, but solid... Mostache bar still to be made.