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4N71B to FS5W71C transmission swap

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  • 4N71B to FS5W71C transmission swap

    Hi guys

    I am new to the forum and hope someone will be able to help me.

    I have an 86 n/a which is currently undergoing a full restoration including NA2T swap as well as the auto to manual swap. The problem I have is I live in the U.K. and there are only 29 Z31's left on the road. I am looking to swap the auto box for a FS5W71C but I am unable to find one for a Z31 here. What I have been able to source is an S13 FS5W71C. Is the Z31 and S13 box the same and can I use it for my application or will it be necessary to make modifications.

    Thanks in advance for any advice

  • #2
    You might be able to source a transmission from here in the UAE and have it shipped. They're plenty. Also, have you tried zcarsource of Arizona? they have the transmissions too, but that might be a big expensive to ship, however still possible.



    • #3
      Only 29!? There were a good deal more when I lived there! Of course, that was back in 2003. You might have better luck sourcing a T5 manual transmission, which they ran in the turbo models, though you'd need a custom driveshaft to run it. Nissan put the T5 in the Z32 300ZXs as well, so they may be more plentiful.
      1985 300ZX Z31 2+2 VG33ET (running!)


      • #4
        Nissan put the T5 in the Z32 as well? Where did you get that info from? Who told you so?


        • #5
          240SX trans is a good alternative but you may need to swap the bellhousing over in order for the 71C to mate to the Z31 VG30 block. You can also look at the RB20 and RB25 trans for an even better alternative. You may also have to swap the bellhousing. You can also use the Z32 bellhousing both turbo and NA for the RB route. If you use the Z32 bellhousing your starter will be facing forward. However I am not 100% sure if the starter will engage the flywheel if you choose to use the Z32 bellhousing.


          • #6
            Have you already asked Nick (user narc on this board)? He has a bunch of Z31 parts. Have you already asked other people on the UK Z31 facebook group? I have a 71C, but I'm in Estonia and I'm not sure how much it costs to ship something that big and heavy to the UK.

            I think I've read that the S13 and Z31 71C are the same internally but have a different bellhousing. You can do some searching about that, you should find plenty of information. Perhaps I could ship the parts that are different if you really can't find one in the UK.


            • #7
              Thanks for the fantastic response. I will try the resources you have all suggested. Especially Zcarsource in AZ I quite often visit Phoenix. Kaur how much would you want for your 71cC I have account with FedEx international so could get a quote for shipping.


              • #8
                If you want to go unbreakable use the Z32 gearbox which will bolt straight up, new improved shift ones may be available at a reasonable price too. The Z32 never used a T5..


                • #9
                  My apologies... I was always told the Z32s came with T5s, as well. I just double-checked, and I am indeed wrong.
                  1985 300ZX Z31 2+2 VG33ET (running!)


                  • #10
                    If you want to go unbreakable use the Z32 gearbox which will bolt straight up, new improved shift ones may be available at a reasonable price too. The Z32 never used a T5

                    Thanks for that z32 are a lot more plentiful here in the U.K. will I also need the z32 rear drive shaft? there are less t5's than 71c's and I believe that only 100 87-89 cars were sold her so the 30a is not possible here either. I have resided to the fact that I will need to ship one, although I have found a resource in Japan were I can get a new one for $1200 plus shipping, but with all the other mods its a little outside my budget.

                    Thanks again guys for the great advice


                    • #11
                      To say the Z32 trans is unbreakable is not true. Infact the weakest part of the Z32 is the trans. Nissan used brass non world class ring baulk for the Z32 trans. Shift a little rough and in no time you will find your trans grind. 4th and 3rd gears are prone to grinding especially down shifting from 5th to 4th and to 3rd. There were too many complaints about the ring baulk failing. Later years Z32 models (98-2000 year models) had vastly improved trans. These are really beefy and the ones to have. Z32 imports ceased in 1996 in the US as it became too expensive to own but the Z32 continued in production till year 2000 in Japan. If you opt for the Z32 trans you will have to source the Z32 drive shaft OR you can also use the RB25 drive shaft which will also fit the Z32 trans. Get the 98 to year 2000 Z32 trans if you can lay your hands on one. If you intend to convert from auto to manual, it will be quite a task. You will need a clutch pedal and an upper pump and lower pump and lay the hydraulic pipes. Easier said than done. If you have plenty $ to spare then get the later years Z32 trans. If you are on a tight budget then source a T5 as these are plentiful and alot cheaper to repair. These are fairy good but some people criticize it for being weak. If T5s are good for the Mustangs it should be good for the tiny nissan.


                      • 260DET
                        260DET commented
                        Editing a comment
                        Sure the later Z32 boxes had a better shift but the earlier ones were hardly rubbish shift wise. Both are good for 500whp which is more capable than any other box mentioned here. I did have an early Z32 box checked internally because race car, it did not need new syncros. Having used the 71C's too, I'd rate their shifts no better than the early Z32's and of course their power handling capacity is a lot less.

                    • #12
                      The T5 in a Mustang is a World Class T5, not the same trans. as in the "tiny nissan".


                      • #13
                        the Z32 driveshaft WILL NOT FIT on the z31. I've been doing a lot of research for the z32 tranny swap since it's in the cards for my car. There's several threads on it. Google search "Z32 transmission maxima flywheel". From what I understand you need:

                        Z32 manual tranny
                        Z32 starter
                        Maxima flywheel/clutch (circa 2000 model year)
                        CUSTOM driveshaft
                        S13 shifter bracket (more custom than S13....)
                        Still have to do something with the speed sensor--- if you have analog gages, I think a pathy speed sensor works. otherwise I'm not sure. maybe wire the Z32 speed sensor in.
                        Master/slave cylinder

                        Other alternative is to swap the Z31 turbo bellhousing (87-89) onto the Z32 tranny. Then a Z31 clutch/flywheel/starter can be used. unsure about the speed sensor

                        Rebuild kits for the Z32 trans are available with the upgraded syncros and forks. might be worth it.
                        Legal stuff:
                        **Nissan Employee**
                        Any information shared is simply my own opinion and NOT the opinion of Nissan

                        not legal stuff:
                        '88 300ZX 2+2-- Under the knife
                        '86 3000ZX 2+2-- the knife victim
                        '20 Leaf SV-- Because I hate burning money
                        '19 NV passenger-- Because my wife likes burning money


                        • #14
                          Thank guys for all the advice But I think I will stick with the 71c as serviceable parts are plentiful in the U.S. ie clutches, master cylinders etc Z32 might be have been an option but cost of transmission/refurb and other parts is coming out around the same price as brand new 71C from Japan. other factor is 71c is easy to wire to auto inhibitor relay. I have managed to source all items required for the swap from the U.S. including an ECU which is having Nistune attached and local engineering company are sorting out drivesaft connection to transmission.


                          • #15
                            The wordings World Class has nothing to do with strength. World class does not signify superior strength or world class strength. BW wanted to have a 5 speed manual shift with one single overdrive to the world market. Hence it is referred to as world class. Mustangs adopted T5s to improve their performances and gas mileage. GM also adoptrd T5s in some of their vehicles.The strength of the trans depends on the alloy of the steel gears (nickel content) and the shape of the gears itself. NWC T5s use brass synchro linings or popularly known as ring baulks while WC uses carbon fibre linings to lessen surface friction for smoother high speed shifts. This is about the only difference between NWC and WC barring all other minute differences which is few and far between them. The strength of the trans depends on the nickel content in the gears themselves and the shape of them and not distinguished by NWC or WC as you might believe it to be. Therefore to say that Mustangs or Camaros have superior T5s (simply because they have WC T5s} than the Z31 T5s is not true at all.