do i have to get a custom driveshaft? or will the stock 1st gen shaft mate right up with a FC trans?



oh, its N/A, not a TII...

I'm pretty sure you don't need a custom drive shaft the stock 12A drive shaft should work fine, And of course the 13B N/A tranny bolts right up to a 12A with out any problems....



But you do have to modify the way the tranny mounts a bit... ( But you prolly know that https://www.nopistons.com/forums/pub...IR )

only real difference is the trans mounts.



86-88 look close, maybe slot the bolt holes, worst case you put the 81-85 tailshaft housing on



89-91 is weird, you have to fab something.

The big dif is the shifer will be in the wrong place.

cool, now i just have to figure out what clutch/pressure plate to use when i mount this up to my renesis...and flywheel too

U can just bolt on a fb tail housing. Then u can use fb cross member and drive shaft. Also u dont have to hack up any thing. I have done this with 86-88. I think the cases are the same 89-91

Does anyone know for sure if you can swap a 81-85 tail housing in place of the 89-91 trannys...????

YES!!! put the two next to each other. the bolt pattern is the same.

i did that long ago t2 trans 13b sixport small flywheel custom clutch disc big spline center to the small disk

i had to grind the bellhousing inorder to get the t2 starter to catch up to the small flywheel it work fine untill my motor blew then add it the t2 engine

and yes custom driveshaft ans cross member

So is it that easy... Just swap out the tail housings..??? Or are there other parts that need to be swapped also..??? (Shift forks or any thing???) https://www.nopistons.com/forums/pub...1047683561.gif

FB tail and shift rod thing don't mess with the forks leave them alone. Get a buddy to help its a little tricky to get shift rod to properly align with the forks.

well looks like I'm going to give it a shot... Probably better then having to get a custom drive shaft made, And to fabricate a custom tranny mount also...

post pics of the process, maybe we could get it pinned for future people...

This tread is going to follow the procedure of installing a S4 N/A transmission into your FB chassis.



Please follow docholidays instructions (Link) for removal of your stock transmission.





Once you have removed your transmission and placed on the ground remove the 8 12mm bolts holding the tailshaft housing to the gear box. Pictured below with green arrows.

Next remove the four 10mm bolts from the inspection plate from the side of the shifter housing. Inside of there you will find the metal block that the shifter ball sits in that connects to the shifter linkage. On the side of this you will find one 10mm set bolt that you will need to remove. Pictured below with a yellow ring and arrow. Once that is done then you can take large screw driver or dull chisel and tap up on the edge of the tailshaft housing to free the silicone seal made by the factory. Once the seal is broken you can lift the tailshaft housing off the body of the transmission, while lifting up reach inside and rotate the shifter linkage out from the gear selector forks. Now that the tailshaft housing is removed from the body you will need to remove a snap ring from above the speedo gear, now you can remove the speedo gear off of the tailshaft. Keep the speed gear as you will need to install this onto your FC transmission tailshaft. Pictured below with a blue ring and arrow.





Follow the above instructions for disassembling your S4 N/A transmission. When you get to removing the metal block from the shifter linkage you will encounter that there is no bolt but there is however a set pin that needs to be removed. This pin will only come out one way so make sure the rolled pin hole is rotated down towards the tailshaft housing. Use a punch to remove this pin.



Now that you have both transmissions apart you can start to reassemble your new hybrid FC/FB transmission. Start by installing your FB speedo gear (which is orange, FC is yellow) onto your tailshaft, then reinstall the snap ring above it. Clean the mating area of the FC gear box and the tailshaft housing from your FB. Once clean you can apply some new RTV silicone sealant to the area. This doesn't have to be a large bead just enough to create a small gasket between the two pieces. Now you can begin to install the tailshaft housing. While lowering your housing make sure to place the shifter linkage into the shiftrod forks on the box or you may have to lift the housing back up to do so. Pictured below with a red ring and arrow. Now replace the eight 12mm bolts back into the transmission and tighten down. With the transmission bolted together you can install the metal shifter block back onto the shifter linkage. Now with that done you can replace the 10mm set bolt through the block and linkage. Clean the inspection plate and mounting surface of the shifter housing and run a bead of silicone to seal the area. Replace the four 10mm bolts to secure the plate to the housing.



Time to reinstall your new transmission into you car. Just follow docholidays instructions above in reverse to reinstall it.



Please note on the swap you will also need to acquire a stock S4 clutch slave cylinder since you will need its longer length to fully engage your clutch.





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