Telling the Difference between Transmissions?
 

Hello everyone =D


So im about to buy a used transmission from a nearby seller and i wanted to know the difference between the transmission so i know im not getting jipped.

I am buying a S4 NA Transmission 5speed

Is there a difference between transmissions? Because im buying this for my 1988 GXL (NA) 5Speed.

Is there some VIN or something different about a turbo one than an NA one?

Also, is there a difference between YEARS. Besides s4/s5? Do i need to watch for this?

Lastly, As im looking at the transmission are there things that i should check to see or know if its in good condition? (Its not rebuilt)

if you do a little searching you will find more info.

there were two transmission designs used in the FC. the NA's used the M type transmission, the turbos use the R type unit. the R type has a removable bellhousing, and a flat pan on the bottom.

the S4's NA's all use the same transmission. the S5 NA got a couple of internal changes, and a shorter 5th gear, which is actually more usable, the S5 GTUs got an even shorter 5th gear. the only external difference that matters is that the transmission mount is different between S4 and S5, however the body remains the same, so its not hard to make it work, you just need to get the right mount.

there is no VIn on the case, and there is no other markings to speak of, you need to be able to ID it. i'd suggest poking under yours.

there really isn't a good way to check its condition without running it in the car. it should spin freely, and you should be able to shift all 5 gears on the floor, but it can still have bad bearings, or synchros.

Thanks for the tips. So look at the way it mounts. gotcha

A s4 has a smoother case then a s5, meaning it has less ribs. I dont have access to the site that has the pictures to show.

T2 transmissions, but you can see the difference in the bracing from the s4 ( top picture), the s5s last 2 pictures

http://www.16paws.com/rx7/images/fd_t2_tranny_med.jpg

http://robx-7.nopistons.com/d/338-1/68ea15c29575.jpg

http://robx-7.nopistons.com/d/1752-2/jan08+001.jpg

The mounting holes for the transmission mount on the S5 are on the side you can see them in the above picture. the S4 are on the bottom

S5 Y-bracket bolts are small and go in diagonal, Y-bracket looks like this:
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[The forum seems to be screwing with me.. this should be centered underneath]

The S4 bracket is a T and the bolts go in vertically, the bracket will look like this:
___
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[The forum seems to be screwing with me.. this should be centered underneath]

If you have an original manual car I've been told there are no meaningful differences between the two transmissions, just be sure to get a matching bracket and crossmember for the transmission.

The S5 5th gear is different

Take note on how the mounts on your transmission look and compare them to the one that you will be buying. I had this problem a few months ago where I got a transmission and DIDN'T notice the difference until it was too late.