Automatic-to-Manual Transaxle Swap

>Has anyone ever attempted an auto to 5speed swap for their '85/86 V6?  I 
>know the 85 manual was a 4 speed and I'd even settle for that if I have to, 
>but I've got to get rid of this auto!

I swapped from an automatic to a 86 4spd, mainly because the tranny was complete with all parts (including shifter, cables, clutch hydraulic line, etc.) and for under $1000 (a great deal over here). I've been waiting for a Getrag car to butcher for 2 years, with no success.

Anyway, here's the scoop: It took the two of us one weekend to accomplish. You will need frequent access to the donor car, since you *always* forget something or lose something, from a washer to a bolt...

First we took the engine out of the bay, separated the tranny and engine and installed the manual's flywheel and a new clutch. Then we installed the manual to the engine and put them back onto the cradle. Now we ripped the shifter cables out of the donor car and put them through the holes on my GT. Time to put the cradle back in! While my friend was reconnecting hoses in the engine compartment, I ripped out the shifter and installed the manual one and hooked up the hoses. To install the clutch, first put in the hydraulic line: remove the oil cooler lines (we cut them before they went up to the radiator, because we didn't want to remove the radiator) and fiddle the line through the rubber grommet in the front compartment. This was really difficult! After that, we removed the steering column and installed the brake/clutch pedal assembly. Next we attached the pedals to the clutch/brake levers and reinstalled the steering column. Removing the park neutral safety switch was easy, and I don't even need the key release lever! Now all we had to do was bleed the clutch , and Bingo!.... Almost... That was last night at 2am(!). The clutch release lever has about half an inch of "dead" play, so the clutch doesn't fully disengage. Well, if we had noticed before, we could easily have fixed that, but we didn't want to pull the engine *again*. So we installed a "fix", a kinda boot that slips over the slave cylinder plunger and prolongs it about half an inch. And that's it.

Was it worth it? Definitely. The car accelerates like hell, and it's not due to the new cat, because the old one was hollow (that's why I didn't pass emissions...)

But it is a *lot* of work, and you need to have expert knowledge of the Fiero, loads of tools and a lifter to work under the car.

Phew, it was a piece of work, but it feels good to finally have a *sports* car... (driving is even more fun now)

>I don't know how the computer works, or if it is any difference for the
>manual vs. auto.

Yep, I copied the eprom from my friend's 86 GT V6 4spd (the donor car was an 85 GT painted red metallic with a gold lower trim... yuck!) It's a standard 2732 EPROM...

Place the tranny in "N" and install the manual transmission ECM PROM... try it out...

>about the '87 4cyl computer.  I wonder if I can just get away with
>changing the PROM.  Do you have any idea?

It should work.

>Also, what did you do with the wiring that went to the automatic
>tranny?  did you just leave it unplugged from the tranny and tie it
>up somewhere?

No. I shorted the transmission start wires on the P/N switch connector. Otherwise you won't be able to start the engine. You also need to connect the VSS sensor on the manual to the VSS sensor connector. I think they fit, but the wires were too short.

I also installed a clutch neutral switch and spliced it into the ignition starter wire. The cruise clutch switch needs to be installed as well, put it in series with the correct cruise brake switch (there are two!). The "Shift Up" light can be connected, but is not necessary. Finally, the Rear Deck Lid Release, which normally works only if you are in "P" or "N", can be wired to the Parking Brake Switch, so that you can only open the deck lid with the ignition off or with the parking brake on. Oh, finally don't forget about the back-up light switch! It is also on the P/N switch connector (I think). If you have a transmission mounted back up light switch, splice the new connector to the old wires. If it is shifter mounted (4spd), short the two wires and splice the connector into the wire passing through the center console next to the shifter. Get the correct color from the manual and go from there. It's not difficult.

From: Oliver Scholz


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