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Rear-end ratios

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  • Rear-end ratios

    What are some of the rear-end gears that will work with a 240sx diff?

    These are the ones that I know of.

    3.54 - early 90's Q45
    3.69 - ?
    3.91 - J30
    4.08 - Stock
    4.36 - ?
    4.63 - ?
    Last edited by jmauld; 08-04-2008, 12:41 PM.

  • #2
    3.91 = J30


    • #3
      Z33 - MT - R200 - 3.538
      Z33 - MT - R200V - 3.538
      Z33 - AT - R200V - 3.357
      Z32TT - R230V - 3.692
      Z32 - R200V - 4.083
      G35 - Sedan - AT - R200 - 3.357
      G35 - Sedan - MT - R200V - 3.538
      G35 - Sedan - AWD - AT - R200 - 3.357
      G35 - Coupe - MT - R200V - 3.538
      G35 - Coupe - AT - R200 - 3.357
      G35 - Coupe - AT - R200V - 3.357
      Q45 - G50 - R200V - 3.538
      Q45 - FY33 - R200V - 3.692
      R32 GTR - RB26DETT - MT - F160 - 4.111 - (Front Final Gear)
      R32 GTR - RB26DETT - MT - R200 (Mechanical LSD) - 4.111
      S15 - MT - R200H - 3.692
      S15 - AT - R200V - 3.916
      S14 - KA24DE - 4.083
      S14 - SR20DET - MT - R200V - 3.692
      S14 - SR20DET - AT - R200V - 3.915
      S13 - KA24DE - 4.083 - (Both R200 and R200V

      Unverified (but speculated):
      J30 - 3.916 - (I found several sources indicating this number but I don't have a J30 FSM so I couldn't truly verify)
      R32 - 4.363
      R33 GTS-T AT - 4.36
      R34 - 6MT - RB26DETT - 3.96

      I just copy pasted this...
      Last edited by a_ahmed; 08-04-2008, 01:24 PM.
      "hexa-dodecahedron-triple-threaded-super-eleventy-way-adjustment-spec" dampers. -Def


      • #4
        what about?

        R32 GTR 4.3
        Xterra front diff 4.63
        NASA HPDE Instructor


        • #5
          Also just found this

          "hexa-dodecahedron-triple-threaded-super-eleventy-way-adjustment-spec" dampers. -Def


          • #6
            Will all of those on A_Ahmed's list bolt to a 240sx diff?


            • #7
              Some of those it would be smarter to just swap the entire pumpkin, but yeah, they should all work in your stock pumpkin. Some of them use 13mm ring gear bolts (as opposed to 12mm) so watch what you're bolting the ring to.

              There's also a 5.1 xterra front diff as well.

              What are you trying to do?
              She's built like a Steakhouse, but she handles like a Bistro.


              • #8
                Right now I'm just researching options. I'll make a post when I have something more that resembles a plan.

                The gist of it is that I've been looking for a lower ratio, and I think that 3.357 will work well.
                Last edited by jmauld; 08-04-2008, 07:25 PM.


                • #9
                  Are you going for some kind of top-speed event?

                  Or just looking to cruise around at a much lower RPM and save some gas money?
                  NASA HPDE Instructor


                  • #10

                    All you do is drill out the bolt wholes in the diff itself. Leave the ring gear alone. I forgot how I did it. Anyways you need the differential shank holes to go from a 11.95ish to a 12.95ish millimeter whole so the 13mil shank on the new bolt fits through. Thats all there is too it.
                    Last edited by Longfellow; 08-08-2008, 08:01 AM.


                    • #11
                      I'd be more worried about the threads you create when retapping it.

                      That said, why not do the easy thing and make spacers for the 12mm stock ring gear bolts. Or you can just leave them be - mine are fine since I didn't have much in the way of machine tools back when I did my diff swap.

                      Or were you talking about reaming out your diff flange holes?
                      '18 Chevrolet Volt - Electric fun hatch for DD duty!

                      DefSport Koni Sleeve and Spring Perch Buy!!!


                      • #12
                        woops, you dont drill out the ring gear, you bore out the non threaded holes in the actual differential so the larger 13mil shank can fit through. Thats all there is too it. The head of the bolt still sits in the recess just fine.

                        The ring gear gets left alone since the thread size on the ring gear will match to what ever bolt you need to put in it.

                        Basically you need a drill, a drill bit and a round file. Although a drill press would be better.
                        Last edited by Longfellow; 08-08-2008, 08:01 AM.


                        • #13
                          Or if you start with an R32 GTS-T VLSD, the carrier already has 13mm holes. Same for S15 HLSD carriers as well as aftermarket clutch-type ones for JDM S14A/S15.

                          I can't think of many applications where you'd want a 3.357 gear. Maybe if you're doing a high torque motor with a Z33 6-speed. Or you're trying to chase down Veyrons, that gear will get you well over 220mph with a stock trans and a nice redline.
                          She's built like a Steakhouse, but she handles like a Bistro.


                          • #14
                            You guys are seriously not thinking outside the box.


                            • #15
                              If you are using a boosted VQ35, then a 3.5 or 3.3 probably wouldn't be a bad idea. I am planning on using the 3.5 from the Z33 MT.