Page 1 of 2 12 LastLast
Results 1 to 25 of 30

Thread: Differential gear options

  1. #1
    M5Hunter is offline Still has a E39 Supporting Vendor
    Join Date
    Nov 2009
    Location
    Hanover, VA
    Posts
    3,749
    My Cars
    E39

    Differential gear options

    Just curious about different gear ratio options to use with the e36 non M rear end. I have read the convertable auto is a 3.91 but doesnt have "limited slip". Can I use the 3.91 ring gear on my limited slip carrier? I know the e30 has a 3.73 but the housing is different. I guess the main quesiton here is interchange ability of rear end parts.

  2. #2
    Join Date
    Oct 2006
    Location
    Naperville, IL
    Posts
    2,462
    My Cars
    1998 540i
    The ring and pinions are the same for all of the e36 6 cylinder diffs.
    Rob
    Prior projects:
    1998 540i with 6.6 LS2/T56 Chevy Power
    - pictures and details
    1992 325i with 6.6 LS2/T56 Chevy power - pictures and details
    1995 M3 with 6.6 LS2/T56 Chevy power - pictures and details




  3. #3
    M5Hunter is offline Still has a E39 Supporting Vendor
    Join Date
    Nov 2009
    Location
    Hanover, VA
    Posts
    3,749
    My Cars
    E39
    so they are all the same? Does anyone make aftermarket gear sets?

  4. #4
    Join Date
    Jul 2005
    Location
    Temecula Ca.
    Posts
    4,489
    My Cars
    99 M Coupe LS Swap
    Why so low? I had a 3:45 in FrankenCoupe and the wheels would spin at part throttle. Not to mention I hit the driveshaft limit up top. A 2.73 and stronger trans on order as I write this message.
    Dan "PbFut" Rose

  5. #5
    Join Date
    Aug 2006
    Location
    Seattle, WA
    Posts
    1,456
    My Cars
    357is (e30 w/LS1)
    We stayed with the 2.93 LSD in our car because the gear teeth in the 188 differential get smaller as the ratio goes up: 4.10 pinion teeth are smaller than the 2.93. Bigger gear teeth = stronger teeth



    E30-LS1 Swap Guide and Kits, email us at e30ls1@gmail.com !!! or check our website e30ls1.wordpress.com

  6. #6
    Join Date
    Jun 2005
    Location
    Portland, Oregon
    Posts
    1,762
    My Cars
    04 Allroad, F20c Lotus 7
    Quote Originally Posted by 357i View Post
    so they are all the same? Does anyone make aftermarket gear sets?
    you can get them up to 4.10 stock in the medium case, I think there might be one higher notch in there - the 4.27 or similar but those are hard to come by. there are bmw motorsport gears up to and beyond 5.x but they are massive $$$

    doing the math in a speed sheet the 4.10 looks like a good fitment - if you can find traction - to the camaro t56 gearing.

  7. #7
    M5Hunter is offline Still has a E39 Supporting Vendor
    Join Date
    Nov 2009
    Location
    Hanover, VA
    Posts
    3,749
    My Cars
    E39
    what car would have had 4.10s in it so I can find one if I decide to go that route?

  8. #8
    Join Date
    Jun 2005
    Location
    Portland, Oregon
    Posts
    1,762
    My Cars
    04 Allroad, F20c Lotus 7
    couldn't tell you which car but there was a FS thread on here from ~6/29/10 that had a medium case 4.10 gear for ~150 bucks - alot cheaper than paying someone else 300+ for one + install.

  9. #9
    Join Date
    Mar 2004
    Location
    USA
    Posts
    3,241
    My Cars
    96 328is 6.0L
    Aren't you making a higher reving engine by going 4.10?
    - 96 328is 6.0L. (LS1 to LS2 build thread: http://forums.bimmerforums.com/forum...ad.php?2098938)
    - 96 328is 5.7L. (LS1 build thread: http://forums.bimmerforums.com/forum....php?t=1289987)
    - 95 ///M3 6.0L. (LS2 build thread: http://forums.bimmerforums.com/forum....php?t=1619249)

    - 97 ///M3. (e46 Fender Flares/track car build thread: http://forums.bimmerforums.com/forum....php?t=1727098)
    - 96 328is (Dual Fuel Pump to Surge Tank thread: http://www.bimmerforums.com/forum/sh...ad.php?1964025)

  10. #10
    Join Date
    Jun 2005
    Location
    Portland, Oregon
    Posts
    1,762
    My Cars
    04 Allroad, F20c Lotus 7
    Quote Originally Posted by bimerok View Post
    Aren't you making a higher reving engine by going 4.10?
    sort of - more torque transmission via multiplication = gears run out at slower mph's

    with a 3.39 diff 1st will spin to 50+mph - with a 4.10 1st will spin to ~35mph with a camaro t56.

    different applications will benefit from different gear sets - if you want less shifting you want a longer diff, if you want more power put to the ground and less top speed you want a higher geared diff.

  11. #11
    Join Date
    Mar 2004
    Location
    USA
    Posts
    3,241
    My Cars
    96 328is 6.0L
    I just remember from my e30-s50 swap when I had 3.9x diff (or some higher ratio) it was very annoying and not practical. I couldn't take the car on highway as it would run close to 5.5K at ~70mph... It was good only for auto-x. Then I switch to 3.25 and man was it beautiful. Just as a stock set up...

    I guess you want to first decide what kind of driving you want to do... Personally I would consider other mods that would increase the power rather then having engine constantly run at high RPMs
    Last edited by bimerok; 08-13-2010 at 08:54 AM.
    - 96 328is 6.0L. (LS1 to LS2 build thread: http://forums.bimmerforums.com/forum...ad.php?2098938)
    - 96 328is 5.7L. (LS1 build thread: http://forums.bimmerforums.com/forum....php?t=1289987)
    - 95 ///M3 6.0L. (LS2 build thread: http://forums.bimmerforums.com/forum....php?t=1619249)

    - 97 ///M3. (e46 Fender Flares/track car build thread: http://forums.bimmerforums.com/forum....php?t=1727098)
    - 96 328is (Dual Fuel Pump to Surge Tank thread: http://www.bimmerforums.com/forum/sh...ad.php?1964025)

  12. #12
    Join Date
    Oct 2002
    Location
    Philly'ish
    Posts
    749
    My Cars
    "Hybrid" E36 M3
    My track only E36 LS2 has the 3.91 rear gear with a limited slip in an E36 188mm diff. TR-6060 transmission instead of the previous T56.

    With the spread of the gear ratio's on the transmission, 5th and 6th gear become very, very usable on a road course so I don't have any complaints. I have run 4.10s in the past in a non-BMW and agree, at high way speeds, it was up there RPM wise. However, with all the torque available, running in overdrive took care of that issue.

    The torque hit from the higher gear ratios has always been a big draw for me. I'm not after the ultimate in gas mileage so the trade-off is worth it. YMMV.

    John

  13. #13
    Join Date
    Nov 2006
    Location
    Minneapolis,MN
    Posts
    2,259
    My Cars
    2003 M5, 2014 535i
    I went with a 3.91 ratio just because the T56 gearing can accomodate shorter gears even in a street driven car. The most I have driven mine was to the exhaust shop this past weekend and 1st 2nd and 3rd are just orgasmic, in 5th and 6th the revs are still low even at high speeds. I happy with the 3.91 choice. MPG results are pending

    2003 M5 LSx l 6 Spd Manual l 4.10 LSD
    Build Thread
    The chassis must always be regarded as a means to an end and never as an end itself

  14. #14
    M5Hunter is offline Still has a E39 Supporting Vendor
    Join Date
    Nov 2009
    Location
    Hanover, VA
    Posts
    3,749
    My Cars
    E39
    where do you come up with 3.91 gears? Is it limited slip?

  15. #15
    Join Date
    Oct 2002
    Location
    Philly'ish
    Posts
    749
    My Cars
    "Hybrid" E36 M3
    No idea. They came with my car when I bought it and yes, its limited slip (added by previous owner).

  16. #16
    Join Date
    Dec 2005
    Location
    Central Valley, CA
    Posts
    2,905
    My Cars
    2011 328xi, E36 LS1
    Most 3.91's I've seen are LSD. I know for a fact they came in automatic 325's with cold weather package (mine). I don't know what other years/models they were in.


  17. #17
    Join Date
    May 2010
    Location
    Southern NH
    Posts
    247
    My Cars
    96 E36 Coyote 5.0
    The E36 I had before this and the one I have now were autos and had 3.91. Unfortunately they both don't have LSD.
    E36 5.0 Coyote DOHC V8 Swap - Build Thread Here

  18. #18
    Join Date
    Mar 2006
    Location
    Memphis, TN
    Posts
    2,473
    My Cars
    95 M3, 01 330ci
    I can get 3.91 LSD carriers.... PM me if you are interested.

    I'm planning on a 3.91 for my M3 as MPG is NOT a concern, power and track performance are. John (Maynor) hit the nail on the head.

    There were LSD and non LSD diffs.... if you got the winter package you got the LSD type thing.

  19. #19
    Join Date
    Mar 2004
    Location
    USA
    Posts
    3,241
    My Cars
    96 328is 6.0L
    I can't seem to find it, but any of you guys remember and have a link to a thread where someone swapped the LSD unit to a non-LSD diff? There was a nice thread with lots of pictures, but I can't find it...

    Thanks
    - 96 328is 6.0L. (LS1 to LS2 build thread: http://forums.bimmerforums.com/forum...ad.php?2098938)
    - 96 328is 5.7L. (LS1 build thread: http://forums.bimmerforums.com/forum....php?t=1289987)
    - 95 ///M3 6.0L. (LS2 build thread: http://forums.bimmerforums.com/forum....php?t=1619249)

    - 97 ///M3. (e46 Fender Flares/track car build thread: http://forums.bimmerforums.com/forum....php?t=1727098)
    - 96 328is (Dual Fuel Pump to Surge Tank thread: http://www.bimmerforums.com/forum/sh...ad.php?1964025)

  20. #20
    Join Date
    Mar 2006
    Location
    Memphis, TN
    Posts
    2,473
    My Cars
    95 M3, 01 330ci

  21. #21
    Join Date
    Mar 2004
    Location
    USA
    Posts
    3,241
    My Cars
    96 328is 6.0L
    Yep. Just found it. Page 7.

    http://forums.bimmerforums.com/forum...ng+gear&page=7

    Thanks!
    - 96 328is 6.0L. (LS1 to LS2 build thread: http://forums.bimmerforums.com/forum...ad.php?2098938)
    - 96 328is 5.7L. (LS1 build thread: http://forums.bimmerforums.com/forum....php?t=1289987)
    - 95 ///M3 6.0L. (LS2 build thread: http://forums.bimmerforums.com/forum....php?t=1619249)

    - 97 ///M3. (e46 Fender Flares/track car build thread: http://forums.bimmerforums.com/forum....php?t=1727098)
    - 96 328is (Dual Fuel Pump to Surge Tank thread: http://www.bimmerforums.com/forum/sh...ad.php?1964025)

  22. #22
    M5Hunter is offline Still has a E39 Supporting Vendor
    Join Date
    Nov 2009
    Location
    Hanover, VA
    Posts
    3,749
    My Cars
    E39
    I did it as well right before Tongboy, but he did do the write up of it. Is as simple as can be and I have put a few thousand miles on it with no problem.

    http://forums.bimmerforums.com/forum...1347123&page=8

    post #200

  23. #23
    Join Date
    Jun 2005
    Location
    Portland, Oregon
    Posts
    1,762
    My Cars
    04 Allroad, F20c Lotus 7
    3.91 LSD's were only offered in early non-asc cold-weather 325 cars - 92-95ish.

    you guys have already found teh swap info - 357i is the one that proved it could be done and take the abuse - I just snapped some more pictures of it - I still love the gearing and think its the best fitment between the lower gears (my original 3.38 auto m3 gearing was WAY too low - I don't know how any of you with 3.25 can drive it around) if you were after track only a 4.10 would right at the top of my list - the 3.91 is good but it still leaves too much of 5th & 6th unused in anywhere but high speed runs.

  24. #24
    Join Date
    Mar 2006
    Location
    Memphis, TN
    Posts
    2,473
    My Cars
    95 M3, 01 330ci
    Quote Originally Posted by Tongboy View Post
    3.38 auto m3 gearing was WAY too low
    You mean way to high (numerically lower)

  25. #25
    Join Date
    Oct 2002
    Location
    Philly'ish
    Posts
    749
    My Cars
    "Hybrid" E36 M3
    Slight tangent... can someone point out where the heck the breather is on these axles? I'm trying to add an extended line and catch can to catch the overflow during track events.. I have yet to see a good picture of where it is located..

    Any guidance?

    John
    John
    E36 LS3

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •