transmission swap
 

How easy is it to drop a transmission from a 89-90 second gen. into a 79 first gen.? And how good is the transmission? Gear ratios? Strength?

i possibly will be more of a headache than ur willing to deal with. i haven't actually delt with 2nd gen trannys, but i do know that u'll have to decide how ur going to deal with the shifter position, leaving it as is or move it back up to match the hole in the car. someone else will have to chime in as to any issues reguarding wheather or not u'll have to swap flywheels or not. u'll also probably have to fab up a tranny mount since it might not align up with the stock '79 mounting under the car.

I just completed putting an 86 NA tranny in my 85 SE. I used the driveshaft, starter, clutch, pp, clutch slave and throwout bearing from the 85. I used the 85 rubber trans mount and crossmember. I had to drill new holes in the rubber mount to match the narrower bolt pattern of the 86 trans. The only problem with the swap is the shifter is about 1.5 inches farther back on the 86 trans compared to the 85. Since this is a gutted race car, I just cut the opening in the trans tunnel. But, for a street car that you want to keep stock, this would be a problem.
According to Atkins, there isn't a whole lot of difference between the first and second gen NA transmissions. The advantage is the parts are still available for the second gen.
Cheers,
Jim

Thanks, Yeah if the shifter is back then I have a problem.

Woundup7 put a TII tranny in his and he was saying that there is a way that you can re-adjust the shifter location. I wish I could be more help but he would be the one to contact on specifics.

Will the tailshaft housing of the 79 trans, fit on the later models? I have been told that 81 and up trans can do this. The second gen trans has a taller 5th gear, which will give a lower RPM on the hiway.

I do believe you can swap the tail shaft from you SA to the the second gen trans.

I'm now considering putiing in a 94-96 Miata Transmission. I heard its good. Can anyone tell me if it really is. How are the Gear Ratios? Can it handle alot of torque? How easy is the swap?

From Felix's: http://members.ij.net/mrmazda/interchange.html#TLENGTH

"Late production 1980 boxes can have the tailhousing and entire shift mechanism from Group 2 or 3 boxes installed for use in Group 2 or 3 cars. The 1980 boxes that have this compatibility are distinguished by their use roll pins instead of cap screws to mount shift forks and fingers to their rails."

Nevermind the Miata thing. But the 2nd gen is still a possibility.

If you're talking about an NA box it should be rather straightforward in a S2/3 car (81-85) but it's a bit of a different thing in a 1979. The shifter location is different, and you can either solve this by swapping the tails (if possible, never done that) or cutting a larger opening in the tunnel and using a S2 centerpiece (dash). BTW, at least overhere, a FC na box is the same as a S3 (84-85) box in terms of mounting etc (different ratios), swaps right over.

I'm only adding to this for those that search....
You can easily install an N/A 2nd gen trans in a 1st gen by removing the tail section of your 12a trans (not the internals, just the housing) as well as the "shifting rod" as well. Do not mix and match the "remote shifter" The 2nd gen's shifter location is further back than the 12a trans. Also, swap the speedometer gears in the transmissions.
It's very easy and painless to do :) Post if you hae any problems doing this.

All of this has been covered and the threads can be found by searching with the terms transmission interchange or transmission swap.

The swap over from the Sa housing to the N/A 86-88 transmission can only be done on a certain Vin Sa and on up but requires that you do a fair amount of work in accomplishing this. It's not as simple as just removing the tail shaft housing and putting it on as you would do with the Fb transmissions when swapping a FC to a Fb transmission. :)

But like I stated there is a thread that already covers this.