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I seem to have successfully got a S4 T2 transmission in my ‘80. Using ultimatejay’s “TII trans shifter relocation video, I got the transmission installed, by wanted to keep the SA shifter. Which is not a drop in solution. In the end I needed a brass bushing and a short shift kit that needed modifications to make this work.
this did stump me for a day, and I can’t remember seeing anyone do this. I don’t know if I should do a write up before I seal it all up. I might just be making things difficult. I don’t know.
Not sure if it's exactly what your going for as the S4/S5 TII and N/A trans differ a bit but i was able to fit the whole SA tailshaft on the N/A FC gearbox just by shortening one of the shift fingers (pics in my rebuild thread) looks like you got yours to fit nicely without though!
different series transmissions. I believe the NA transmissions are designated "M" and the turbo and ribcaged transmission from the 70's are designated "R" . The R transmission has a larger output shaft. I believe swapping tailshafts are impossible.
@Richard Miller I'd like to know what you did to retain the SA shifter. I'll be using an s5 NA transmission but I'd still like to see it. Thank you!
First, let me say I may be an unreliable narrator, so “trust but verify”
As mentioned above , there are two styles of rx7 transmissions. Previous to installing the “r” turbo transmission I had a 84’ NA 5 speed adapted to have a SA. I believe you are saying that you will be “using a S5 NA transmission” This helps to an extent, The trouble is you have an early 79, which I believe the shift fork rods are threaded in the early NA transmissions . Why this matters is the shift linkage will need to be shortened in the S5 transmission or you will need to have the SA shift linkage modified from being a threaded to a smaller hole for a rolled pin . I had a fabrication shop do that. ($100 or so). The later SA transmissions used the rolled pin so if you had a ‘80 build you might not have the bolted shift linkages. Oh, this becomes a hybrid of a SA tailhousing (and shifter) and the S5 NA transmission,
So, it’s been a few years since I did this. All knowledge was gleaned from this forum.
First, let me say I may be an unreliable narrator, so “trust but verify”
As mentioned above , there are two styles of rx7 transmissions. Previous to installing the “r” turbo transmission I had a 84’ NA 5 speed adapted to have a SA. I believe you are saying that you will be “using a S5 NA transmission” This helps to an extent, The trouble is you have an early 79, which I believe the shift fork rods are threaded in the early NA transmissions . Why this matters is the shift linkage will need to be shortened in the S5 transmission or you will need to have the SA shift linkage modified from being a threaded to a smaller hole for a rolled pin . I had a fabrication shop do that. ($100 or so). The later SA transmissions used the rolled pin so if you had a ‘80 build you might not have the bolted shift linkages. Oh, this becomes a hybrid of a SA tailhousing (and shifter) and the S5 NA transmission,
So, it’s been a few years since I did this. All knowledge was gleaned from this forum.
I think we've misunderstood each other or I'm really tired. Sorry, Is this what you did in your original post with the R transmission? Thank you!
The turbo trans that is in my car, required the shift rod to be cut down and drilled for a rolled pin. And the shifter housing to be cut down. I referenced the tutorial in my first post. To use the SA shift lever I used a short shift kit and some shimming as the fulcrum point is longer on the SA than the FC. A brass Miata shifter bushing was used to get the smaller SA shift lever ball to fit the larger FC socket on the shift rod
The turbo trans that is in my car, required the shift rod to be cut down and drilled for a rolled pin. And the shifter housing to be cut down. I referenced the tutorial in my first post. To use the SA shift lever I used a short shift kit and some shimming as the fulcrum point is longer on the SA than the FC. A brass Miata shifter bushing was used to get the smaller SA shift lever ball to fit the larger FC socket on the shift rod
Awesome information. Thank you! When I get around to doing this I'll try to remember to document and provide an update here!
Taking notes as this seems to be the route I'll inevitably take in the future for my '80 as well. Getting tired of swapping all these NA transmissions.
Yeah but the T2 transmissions don't like to shift at high RPM
That's the main thing that kept me breaking smoothcases instead of upgrading. I did an end run around the problem by upgrading to a stock 12A so hopefully transmissions last longer than oil filters
Yeah but the T2 transmissions don't like to shift at high RPM
That's the main thing that kept me breaking smoothcases instead of upgrading. I did an end run around the problem by upgrading to a stock 12A so hopefully transmissions last longer than oil filters
I mean I'm on my sixth (?) smooth case due to bearing noise. Plus my engine isn't set up for high rpm anyway (at most I hit 8k, shift light goes off at 7k). I just need the torque holding capacity they provide for my turbo setup.
Awesome information. Thank you! When I get around to doing this I'll try to remember to document and provide an update here!
Ok, so here's my update in regards with using an SA shifter in an S5 FC NA transmission. It's more or less exactly as described. The only difference I encountered was I think my SA shifter may not be stock. When I went to pull the shifter out I noticed that it was already on a "short shifter" spacer. That spacer was about 20mm thick, same thickness as the "short shift" space that came on the FC trans. On the side of the spacer was scribed "SA". I've never seen an SA shifter before but the ball end was 17mm and the fulcrum ball is ~50 mm up from the bottom of the shifter to the bottom of the ball. Or about 66mm from tip to center of fulcrum ball.
The S5 NA transmission that I have had a plastic spacer in the shift rod socket that I replaced (someone on ebay made nylon reproductions), I didn't catch the measurements but its around 17mm if not a millimeter or so larger ID.
Outside of my different(?) SA shifter everything went smoothly, as expected, I just wanted to provide an update as I mentioned before. If anyone wants any additional measurements act fast while I still have things apart!
Tangential to the topic: If you're developing high torque, consider upgrading the gears to the physically widest sets available. I cleaned all the teeth off of my T2 trans. After upgrading with wider gearsets from an FD, I haven't broken it again.
