Hey guys, those who have done these swaps, pls i have some questions i need answered...

F23 M86: Will this tranny accept fiero axles? Will the stock cobalt axles fit the Fiero hubs? Will one of those jack shafts (or half shafts) fit into the f23 and will a fiero axle fit into the jack shaft?

Same questions for the f35 and f40 trannys... I really wanna use the f23 tranny with the jack shaft and 2 drivers side Fiero axles...will that work? if not, what can i do to make it work...(like using Cobalt axles if they are compatible)

Thank you everyone!

Also theoretically...can I hook up a 5 speed getrag shifter (inside the car) to a 6 speed F40???? Will that "transform" my 5 speed shifter into a 6 speed?

It would help if you pick a transmission...

One of the primary reasons people pick the F23 is because stock Fiero axles are used with it. No need to mess with a jackshaft, so most don't use one. I don't know of anyone who has installed an F23 with a jackshaft, so you will likely need to R&D this one if you want to use it.

The F40 and F35 can both use the Cobalt SS (supercharged version, not the turbo version) axles and intermediate shaft when installed in a fiero. The F35 would place the engine in the approximate stock location, the F40 would shift it 1" to the passenger side (which there might not be room for - like many of the V8's).

For the F23 or F35, you can use any shifter you want as the reverse lockout is part of the transmission. On the F40, its not part of the transmission and the Fiero 4 speed shifter is needed since it has the reverse lockout built into it.

[This message has been edited by fieroguru (edited 03-20-2014).]

That was super helpful! Thanks man, so if im reading this correct...

I can use the f40 with cobalt supercharged axles and jack shaft...but the 5 speed shifter wont work with the 6 speed, but the 4 speed shifter will!

If i use the f35, again use cobalt axles and jack shaft...and i can use my 5 speed shifter just fine?

Correct. The engine placement of the F35 will be very similar to a stock fiero, but the F40 will need it to be 1" further to the passenger side and some engines don't have the room on the passenger side for this shift (mostly the V8's).

The F23 and F35 can use a fiero thickness flywheel (about .82"), but the F40 needs one that is much thicker.

4 speed shifter when used with the F40 needs modified (expand the slots to allow the 4th shift gate and to relocate one of the cable brackets on it).

Custom shift cable brackets will be needed on the transmission side for any of the 3 transmissions and the needed shifter cables depends on your cable bracket design. If you use 2 Getrag select cables, you will likely break the one used for shifting - it simply isn't large enough for agressive shifting.

Custom transmission mounts are also needed for any of the 3 transmissions.

Oooo issues...

The tranny brackets will be made by Roger Thelin, (im getting his kit) but your saying the 4 speed shifter will have to be modified...dont really wanna do that...does the 5 speed getrag shifter need to be modified for the f35? And do you know what cables i would need, right now i have dickmans cables...sorry im a little confused..

quote Originally posted by 4thfiero: Oooo issues... The tranny brackets will be made by Roger Thelin, (im getting his kit) but your saying the 4 speed shifter will have to be modified...dont really wanna do that...does the 5 speed getrag shifter need to be modified for the f35? And do you know what cables i would need, right now i have dickmans cables...sorry im a little confused..

If you want to run the F40 with 2 getrag select cables, then yes, the 4 speed shifter must be modified. The modification involved opening up a slot and relocating a shift cable bracket (cutting/welding).

I don't have much info for the F35 as it is only used with some of the ecotecs and there have been very, very few swaps with that transmission into a fiero. You might want to read this thread in detail as it uses the F35 transmission and the Thelin parts. Most of your questions about F35 items are probably covered in it. If not, you might try to PM ccfiero350.
https://www.fiero.nl/forum/Forum3/HTML/000094.html

thanks for all your help, i did pm the guy who posted that forum...hopfully he can shed some light.