Monday, November 2, 2009

50. BMW E36 Differential Ratios

Additional info:

316i (M43) - 3,38
316iA (M43) - 4,44

318i - 3,45
3,46 South Africa
318iA - 4,45
318i (M43) - 3,38
3,46 Australia / South Africa

318is/ti - 3,45
318is/tiA - 4,44
318is/ti (M44) - 3,38
3,45 USA / Canada
318is/tiA (M44) - 4,44

320i - 3,45
320iA - 3,45
4,10 USA / Japan

323i - 2,93
323iA - 2,93
3,64 Japan
3,91 USA / Canada

323ti - 3,07
323tiA - 3,23

325i - 3,15
325iA - 3,15
3,91 USA / Canada
3,73 Japan
3,64 South Africa

328i - 2,93
328iA - 3,07
3,91 USA / Canada
3,46 Japan

M3 - 3,15
M3 (S50B32) - 3,23

318tds - 2,79

Note: BMW E36 M3 had a 2-way 25% limited slip differential.


  1. THANK YOU VERY MUCH!! THIS IS THE INFORMATION I WAS LOOKING FOR ALL DAY LONG! my e36 328i differential is making huge grinding noise anytime the car is rolling... i guess it's time to swap it, i just wanted to have a reference as to what options are open to me.

  2. No problem :)

    Well, You can put any diff on your car. As long as it fits in your differential case. That's why I love BMW - you can easily customize it so it suits your needs perfectly.

    If I were you, I would swap in a diff with a shorter ratio, for more acceleration. But, that's just me. :)

  3. 325 iA Europe 3.73

  4. Now that's a diff ratio! :)
    Thanks for the info!

  5. Hello,
    Can I put M3's (S50B32) 3,23 ratio lsd diff on my E36 325 (M50B25TU) 3,15 ratio standard diff ?
    Is it compatible ?


  6. European M3's have a bigger differential than non-M cars.
    And, the flange (the one that connects to the drive shaft) has 6 holes (opposed to 4 holes on non-M cars). So, you would probably have to replace the flange on the M diff with a standard one. The diff casing (Rear axle carrier) is bigger on the M3 (to accommodate a bigger diff). So, you would need to swap that too. I can't really tell you anything about the otuput shafts... I don't have them yet, but I suspect that they need to be from an M car as well...

    Hope this helps. :)

  7. Ah, I forgot to mention - US M3's have the same size plug'n'play differentials like regular cars

  8. I see...
    So my choice is 3.15 from E36 325 or US M3.
    What about EU M3's 3.0(S50B30) diff casing ?
    I live in Greece so it's easier to find one here in Europe...

    Thanks for your help.
    Nick from Athens

  9. Hi Nick!

    I bought an 3.23 M3 3.2 diff (EU - I live in Slovenia) and big diff casing for 400€.
    I still need to swap the flange on the diff, so I can bolt it to my drive shaft, and I probably need to buy the output shafts as well.

    So, as far as I know - big diff case and M3 diff with small modifications will fit to your E36. If you can find one - go ahead and buy it.

  10. all diffs are exsactly the same, 316 to 328 or m3. no mod is need.normal or slip.i've a 328i with a m3 diff and it matched mod was needed.but you have to notice putting a highed diff will affect you accelerration, my 328i was spinning with 3th gear at 150km/h and now with the limited slip diif of the m3 it only spings at 120kmh in 2th gear or low 3th.but i can be done without mods.

  11. @dkoscuhuch:

    True, if you're talking about US-spec M3 diffs.
    Euro-spec M3 differentials are bigger than other.

  12. I just found a 4.44 lsd and the owner off it doesnt even know the difference from a manual open diff... its off a 318tiA, mine for €150... lol not selling it though, its going on my 318is :)

  13. @Richard:

    Want to trade for a M3 diff? ;)

    Consider yourself extremely lucky. Go play the lottery or something...


  14. Hi,
    im new to diff ratios but was wondering if a 325i diff off an eu model would speed up my 320i eu a bit ?
    any help would be appreciated

  15. Hi!

    You would gain some top speed, but you would loose on acceleration.

    Basically, higher diff ratio number means faster acceleration and lower top speed.


  16. i have a 95 M3 E36 coupe, and the diff is making noises now, the car is modified and i love the speed, what should i replace my LSD with, what ration or should i get OEM ?

  17. There's nothing wrong if you get another OEM diff...

    If you want something better, go for Quaife.

    What version of the M3 do you have? Euro? US? There's a big difference in diffs...

  18. hi, I just bought a 323ti, with a bored out engine to 2.7l. With some ecu work it gives me around 230bhp. Now, would it be possible to swap the original diff with one from a 328i? accel is good, but I need if for motorway travel to the green hell;)


  19. As far as I know, 323 and 328 diffs are exactly the same.
    You should go for a 318tds (yea, diesel) diff if you want some more top-end speed, since 323 and 328 already have the longest diffs.

  20. @Marin Malnar
    thats not exsactly true, the 328i i have has an m-tech suspension and rear axle, at the time i broke my first m3 lsd i mountent a 3.45 diff from a 320i until i found a new lsd with no mods needed just plug and play and they are EU diff all of them so i quest they're no mods needed in any diff.

  21. hello, im dave and ive bought an m3 evo complete back axle with 3.23 diff. this is being fitted to my 99 m44 318is. i also bought an m3 evo prop but does anybody know anything about propshaft lengths? what will it take 2 make it fit my 318is?????

  22. @ Dimitri:
    There are 3 sizes of diffs:
    - Small (4cyl)
    - Medium (6cyl, US M3, M-tech)
    - Big (Euro M3)

    Of course, you're playing with the medium size diffs. Everything is plug and play because they are the same size. If you would switch to another size, you would have to change the complete rear subframe. (Diff housing, shafts... etc... etc...)

    @ Dave:
    Um, as I was told, propshaft should fit. I was told that the best way to fit the M3 diff is, to replace the 6-bolt M3 flange on it, with a regular 4-bolt one, and to use your current propshaft...
    But, I didn't try it... so I can't confirm the info.
    Well, you could always raise your car and take a couple of measurements. ;)

  23. @martin
    Before i swap the engine i had a m43 engine on it with a 3,45 diff from the 320i with no mods everything fitted perfectly. after i change to the m52b28 for a short time i had the old diff with the old suspensions and the rear axle.( i changed that after of course) and i had no problem, sure if you want a m3 euro diff you have to change some stuff like the motion axles but that not a bif game. you can fitt every diff with almost no mods.

  24. hallo my frind i have e36 318is m44 ingen frome japan wt the best diff can i use to get good accleration and my car befor is 316 ia and i stell work wz orginal diff come wz car and my car come frome germany

  25. @wael:

    If I understand correctly - you have a m44 engine in a car that was a 316.
    If you have the stock 316 diff (3,38) - you can upgrade to a stock 318is diff(3,45), or to a 316/318/318i (Automatic transmission) Diff (4,44). Now, that would give some brutal acceleration :)

  26. hi
    im from n. ireland was just wondering if a 318is lsd would suit a 328i which is stock.i would like better acceleration just. would the ratio be to shrt for the motorways??

  27. Hi!

    I'm not sure if the 318is diff would even fit on your 328.
    I think 318 uses the small diff casing, and you have the medium one. If you want a small diff, you'll need to replace your diff carrier (and probably the drive shafts) as well...

    Go for a 325 diff. That should give you some acceleration, and still be OK for motorways.
    318is diff would be too extreme, IMO. :)

  28. Hi,

    I have a complicated problem...

    Car: 1994 RHD 325i manual

    Current gearbox: Euro M3 3.2 6-speed

    Current diff: Medium 188mm from Japan 328i auto 3.46, rebuilt with LSD and incorrect 6-bolt flange (turned out to be for the 80mm bolt pattern diameter CV joint for some E39/E34)

    Current prop shaft: Euro M3 3.2 6-speed but final section chopped off and welded with a possible E39 final section with the 80mm bolt pattern CV joint. Chopping done without my authorisation! Very pissed!

    My plans to put things right:

    I need to rebuild my rear diff with the correct 6-bolt flange (86mm bolt diameter pattern) which I will try to source.

    And to use a whole original Euro M3 3.2 6-speed prop shaft, without any cutting up this time!

    Question: Will the M3 3.2 prop shaft have the correct length to reach the medium 188mm rear diff? I know the Euro M3 3.2 comes with large 210mm rear diff.

    Thanks in advance!


  29. hi, I have 1997 M3 3.2 (coupe)japanese... so my differential ratio is 3.23???

  30. @ ///Mixan: Yes, I do think it's 3.23

  31. @ Paul:

    If my information is right, then the Euro M3 3.2 propshaft lenght is: 1367MM. 325 propshaft lenght is 1512MM. I don't really know if the M3 diff is longer, or is it the gearbox.

    My guess is, that the M3 shaft is too short (too big difference in lenghts???), and that you'll have to use a 'shortened' 325 propshaft.

  32. Hi @Marin,

    Thanks for responding, the longer propshaft for 325 manual is due to the smaller gearbox housing, the 6-speed M3 gearbox is really huge!

    The distance from the propshaft centre mount bearing to rear diff input flange is the one I have to figure out...



  33. Hi, I'm planing to do drifting and i have a m3 e36 with 3,15 ratio and i would like to change it to a lower ratio for more torque what would you suggest ,i already have a helical lsd from obx and work's perfecly but i don't have enough power on lower rpm's .
    thank you

  34. I just blew the diff in my 318is car is running a 2jz out of a supra what would be a stronger better diff that will bolt straight in with no mods to the standard m44 318is ???

  35. Well, the stock 318is/m44 diff is a typ 168.
    That means, you're unfortunately stuck with the small diff. (Considering you want a bolt-on solution)

    Since you have quite some power, try getting a 316i or a 318i diff, it's got a bit longer ratios. It just might last a bit longer.

    If not, my guess is, that you have to go aftermarket.


  36. If i wanted to swap to a 6 cyl diff wat would i need to change??


  37. i have a 318is coupe and have found an m3 LSD with shafts will this fit straight in?

  38. @Anonymus:

    Can you tell me what kind of M3 are we talking about?
    US, European 3.0, European 3.2 ???

    Whatever the case may be, you'll have to replace the input flange and the diff carrier (I believe you have the small type 168 differential). Probably some other things as well, like the drive shaft.

    So, the quick answer is - no, it won't fit straight in. (If your car isn't modified already.)

  39. I have a 318is that I did a auto to manual swap on and ever since i did the swap my rpm's are super high even in 5th gear ill be doing about 70 and my rpm's will be at like 4500k i bought a new diff because apparently I need to put a lower ratio than my 4:44 the one im about to put is a 3:91 If anyone can tell me if it will make a difference before i put it on please let me know so i dont have to take it out again and buy another lol

  40. There's going to be some difference, that's for sure. I just don't really know how much. Replacing the diff isn't that big task... go ahead and put it on. If you won't like it, you can replace it - it's going to be a lot easier and faster doing the job the second time. :) (the know how, and already loosened bolts...)

  41. Hi Marin,

    I live in the UK. Would a 1997 323i diff fit my 318is of the same year?

    Many thanks,

  42. Sorry but the 320i is a straight six and it also has a small case cause there is not a lot of info on it.