E36 M3 3.2 evo LSD Diff 3.23 ratio big 210 case

I'd be interested to see how this works out as there are plenty of those diffs around and 3.23 seems a good less extreme ratio compared with 3.64 or 3.91

Diff ratios depends a lot on what car you have, and different ratios work different on different E31's.
It all comes down to if you have a 850 or 840, US or Euro, 4-speed auto, 5-speed auto or 6 speed manual.

A 3.23 will work well on 850's as the euro M70 4-speed auto come stock with 3.15, though I doubt you will see much of a difference to a 3.23, so look for a 3.45 or 3.64.
The M74 came with 2.81, and again a 3.15 is a good swap
Almost alls 6-speed manuals have a 2.93 diff (except the 4.4 840 that has a 3.08), a 3.23 swap should make it a little quicker, but it might be just as good to get a 3.15LSD from a 750.
840's have different ratios based on if it is a 4.0 or a 4.4.
I believe the 4.4 has a 2.81 diff, so changing to 3.15 should make ha pretty impressive difference.
The 4.0 has a 2.93, again a 3.15.

So in a way the only ones that should be looking at a 3.23 are the ones with a 6 speed manual.

As I see it, unless you have a M70 850 4-speed auto you should be looking at a 3.15 LSD from an e32 750 (88-90 model)
If you have said 850, then a 3.64 may be the way to go.

I was JUST about to buy that..........

Let us know how it turns out

Just a tip...:)

I did this swap on my 840. It was a 3,91 from a e34 m5. On mine, the 12 bolts on the two output shafts was different threads , so i needed to buy new bolts also.
I'm not saying you need new bolt, just be careful to not force them in when mounting the output shafts, just in case..

Terminator: with your 3.91, do you find any problem with gear changing back up a gear when going very fast and having done a kick-down? I find that the gearbox is having a problem changing up fast enough when accelerating hard.

With my M73 I went from 2.93 (stock) to a 3.15 diff and the difference was just right, car is much livelier and a lot more fun. I was going for the LSD option but I bought a Quaife ATB in the end.

If anyone's interested, I still have the LSD unit and the correct long diff case plus my original 2.93 Crown Wheel and Pinion set available (or you could fit whatever you want in the case, the unit is currently disassembled)- let me know if you're interested and I can sort out a price.
Cheers

Zitat von Argonaut;110366

I still have the LSD unit and the correct long diff case plus my original 2.93 Crown Wheel and Pinion set available (or you could fit whatever you want in the case, the unit is currently disassembled)- let me know if you're interested and I can sort out a price.
Cheers

Hi Jason,
I've got an upcoming little job coming up with my propshaft. and thinking seriously about a 3.15 swap because it will be the right time to get everything done at once (funds permitting..i've only just emerged from a deep financial trough of my own digging)...

Are these parts located in the UK?
Also, a brief query in case the answer to that is yes:
I want the LSD for sure, but a 3.15 minimum so I'd not want the 2.93.
Can i buy/ use your LSD and your big case, but get a 3.15 in there somehow? .. Or are the 2.93 parts integral to the LSD? Happy to take your advice if you know! thanks
Thanks
b

@Burn
the diff in the M62 is 2.81 ex factory so a minuscule effect ought to be seen if going up to 2.93. The output flanges need to be swapped in from yours (M62 - hole diam. 94mm, M73 - 102mm).

Last I heard Jason is living in the same UK you live in

Cheers
Reinhard

Zitat von BBMatic;110489

I want the LSD for sure, but a 3.15 minimum

Reinhard, dear boy I know my posts are waffling and ill informed but you can't have read the bit I snipped here?
However thanks for the tip about flanges/ J's current whereabouts..
To clarify: I think a 3.15 will suffice but unsure about internals swapping, hence my query to Jason about using the long case & the LSD unit-- but NOT the 2.93 crown/pinion etc. Maybe they're not separable, if thats what you mean?

Sorry - just wanted to point out that even the move to Jason´s 2.93 might be noticeable in a positive way.
Others having gone that route will hopefully chime in.

Reinhard

Noooooo ... never apologise Reinhard!
That wasn't my intention.

Just wondering, if anyone knows...is it workable, using Argonaut's big case and LSD unit, but finding a 3.15 and using that with his LSD?
Or, is his LSD and the 2.93 parts wedded together, as it were?

Zitat von anguswolfendale;110361

Terminator: with your 3.91, do you find any problem with gear changing back up a gear when going very fast and having done a kick-down? I find that the gearbox is having a problem changing up fast enough when accelerating hard.

Hey Angus!

I now have a manual gearbox in my car, but i did NOT have any problems with the autobox after the diff swap.
So if you have a problem, it should not be caused by the 3.91... I drove min in several months without any issues .

If you need to swap the input shaft , you really need to know what you are doing, this is not for a hobby mechanic. (not that i'm saying you are)
I'm no expert , but tightening the nut correct is very important , this is because of the clamping bush (number 8 on picture)
If this isn't done properly the diff could start howl after a short while , or even worse brake down..
8er.org/forum/index.php?attachment/21973/

Zitat von BBMatic;110496

Noooooo ... never apologise Reinhard!
That wasn't my intention.

Just wondering, if anyone knows...is it workable, using Argonaut's big case and LSD unit, but finding a 3.15 and using that with his LSD?
Or, is his LSD and the 2.93 parts wedded together, as it were?

Hi Mate, sorry, I haven't been online much today so only just read this. The 2.93 is not wedded to the LSD - in fact at present it's not even fitted. I bought the complete unit from a chap in the USA and then had the bits dismantled and used only the 3.15 CWP set - that's why I still have the LSD, the case and the 2.93 available - I fitted the 3.15 into my original case and used a Quaife ATB instead of the LSD (I still had enough money to spend on such things back then).
So, to answer your questions as best I can, AFAIK, you can use the case with any crown wheel and pinion set designed to be housed in the big case. I have no problem in letting you have the LSD and the case if that's all you need, however, as Reinhard pointed out, even if you only went "up" to 2.93 you would notice the difference. Remember I went from 2.93 to 3.15 and noticed a big difference for only a small ratio increase. I' now living in Hastings but the bits are in Norfolk - no problem to get them to you in London though.

Let me know what you think.

@All readers: please chime in and correct/advise ref what CWP sets can be fitted in the long case so that Bern is better advised, thanks!

Zitat von reinhard;110493

@Burn
the diff in the M62 is 2.81 ex factory so a minuscule effect ought to be seen if going up to 2.93. The output flanges need to be swapped in from yours (M62 - hole diam. 94mm, M73 - 102mm).

Last I heard Jason is living in the same UK you live in

Cheers
Reinhard

Just to add to this that the big case I have available is likely not from an M73 - I don't actually know what it came from but I originally bought it from Randy Craddick in the USA. I will have a look at it this weekend when I'm up in Norfolk and can get my hands on it, I'll check for part numbers, identifiers etc and then perhaps we can better identify what it's from. My point being that the flange swap might not be needed.

Zitat von TERMINATOR;110499

Hey Angus!

I now have a manual gearbox in my car, but i did NOT have any problems with the autobox after the diff swap.
So if you have a problem, it should not be caused by the 3.91... I drove min in several months without any issues .

If I disconnect the batteries I understand this will reset the gearbox and then it will "learn" the new style of driving with the 3.91 LSD
.