hey, is there anyone here who has successfully converted a 12a 3 speed automatic to a 5 speed that would be willing to let me call them and ask questions on a few things.... i dont wanna tear into it and find out something i wish i found out before i pulled the engine...


pm me if your willing to "tutor" me

thanks

-greg

 

Yes I have done this . after I finished I swore I would never do it again. The tought part is puting in the clutch peddle. I,m 6'2' 200 LBS A smaller person may have an easier time. take out the driver seat and you still have a very small place for you hands to work Its been more than five years since I did this. the good news is I'm still driving the car. The conversion was further complicated by the fact that I put a 1980 five speed into a 1981 chassis. but that part wasn't too difficult

 

Ok I have done this, and it really depends on which year your car is, as the 84-85 ones are more difficult. Because the 84-85 cars have an overdrive auto tranny, the tranny is actually longer than the 5spd. As a result the mounts are 4 inches farther back.

What you would need to make is something like this:



You need to get the brake and clutch pedal set from a manual car. the pedals bolt right up, theres even an open connector for the clutch switch. Be patient, the pedals are the hardest part of the project because you have NO works room under the dash.

Next you need remove the flexplate for the A/T. I'm assuming you are just going to use the stock flywheel, so you need to remove the auto transmission counterweight. Install the flywheel and torque it to 350 FT/LBS. You then need to install the pilot bearing. After that is done get a clutch alignment tool and install the clucth disc and pressure plate. After that install the release bearing in the M/T. You now need to connect the engine up to the transission. You also need to get a top dust cover for the motor as the A/T one extends onto the transmission itself.

After you have bolted everything up, you need to remove the auto tranny wiring harness, and install one from an 83 or newer car. One from an ealier year car may work, but I havent tried it. After that, you need to pull up your passenger side carpet. You will see a metal kick pannel, remove it. Under there will be the ECU and the A/T control unit. Dissconnect the A/T control unit. Put back down the carpet and presto, your done!

The last part is to start the car, the carb may need to be adjusted as manual and auto cars are set to run differently from the factory.

I'll take a bow now!

 

OOPS, just read your post and you said a 3spd auto to a 5 speed. Ignor the mounting problem. Everything will just bolt up. You do need to get a crossmember from a manual car though. Its also a good idea to start out with a new transmission mount as well.

 

that pic looks alot like my auto to manual swap conversion kit

Only difference is my brackets are stepped, the brackets in the pic above would lower your trans height the thickness of the brackets

my kit is also for the 2nd gen

 

since he is swapping a 3 speed auto that means his car is a 79-83 model. on those years the trans mount is interchangeable (auto to stick) so he just needs to get a manual mount. the 84-85 auto trannys are longer , thats why the mounts are in a different spot.

if you need any help please call me

 

What about driveline lengths?

~T.J.

 

Why would you need another wiring harness?

 

The auto tranny has different sensors and conectors than the manual. The wiring harness is just a plug and play thing though. Just follow the wires that go to the auto tranny back to the plug on the drivers side inner fender and unplug it there, plug in the harness from a manual, and hook up the wires to the manual tranny and youre good to go.

~T.J.

 

Okay, so the wiring harness is modular and all I need is the manual transmission's wiring harness (what exactly does this constitute?) rather than an entire engine one?

Please be patient with me, it's been a while since I've had a first gen.

 

680rwhp12a... whats the number to the shop there.. i will more than likely be calling you next weekend when i start the swap...

thanks

-greg

 

im using an se driveshaft in conjunction with the se tranny... this will be no problem as ive been told by a few guys over at mazspeed

-greg

 

Yeah, the harness is modular. Its the harness that controls the reverse lights, and some other misc. little things down in there. I could go take a picture of the one from my 83 GSL if you want. The plug was cut off when it was stolen (dont ask me why, lol), but I have the plug and the harness so you could see what it would look like together.

~T.J.

 

I had this swap done on my old '83 several yrs ago and the tranny mounts were not interchangeable - a bracket had to be fab's and moved back for this application too.

 

RotorMotorDriver: I'd appreciate it if you could take a picture or two, as I don't have a good manual currently.

 

Gregs you might want to look at Felix's How-Do-I.

 

No problem. Im assuming this is the harness that you need to switch out. Its the only one that goes down to the transmission from the engine bay, but Ive never done this swap, so I dont know 100% for sure. Anyway, it controls the revers lights, it has the little spade connector that goes to the starter solenoid, and one other plug that goes into the tranny. The wire colors are (2) black w/yellow stripes, (1) blue w/white stripe, (1) green w/yellow stripe, (1) red w/white stripe.




~T.J.

 

818-576-9191

 

Thanks a bunch.

 

What about the engine counterweights?

 

What about the idle compensator thingy, I hear thats not on an auto engine, and those 2 vacuum things mounted to the dizzy, I hear there is one on an auto, and 2 on a manual. And wasn't there a few solenoids that needed to be removed?

 

Goddammit! Where was this kit when I did my conversion?!?! Wait its a second gen kit. Oh well, but if you notice at my pic there is another peice of the bracket material inbetween the transmission mount and the tranny to make up the difference.

When I first did it, I didnt have the spacer like I do in the pic, but it was cool, because it looked like I had a short shifter!

 

here is my step by step process i have written up..

veterans of this swap please correct anything or add anything i have forgotten


1. prep engine/trannyt for removal
2. label every hose and wire that is removed from the engine
3. remove driveshaft
4. unbolt and lower the tranny mount..
5. hook up chains to engine
6. unbolt the engine mount
7. pull the engine
8. remove the automatic transmission from the engine
9. remove the torque converter
10. remove the automatic flywheel
11. put on my 83-85 12a flywheel, torque to spec
12. install the pilot bearing
13. install clutch and pressure plate
14. install 5 speed tranny to motor
15. install clutch slave cylinder to tranny
16. re- install engine and tranny .. bolt everything up and torque to spec
17. re- install drive shaft, torque to spec
18. hook up hoses and wires back onto engine
19. install clutch pedal assembly
20. install clutch master and hardline and hook up the softline to the slave cylinder
21. bleed the clutch master and slave
22. figure out the ignition for the 5 speed..
23. disable the automatic control from the ECU (dont know if applicable to pre 83)
22. DOUBLE CHECK EVERYTHING AND MAKE SURE EVERYTHING IS HOOKEd UP RIGHT

-greg

 

Why do you have to remove the engine?

I'd think that you could just block the engine up and use a transmission jack to remove the tranny from under the car.

 

i have to remove the engine.. i have to remove and replace the flywheel..... i have been told you cant do it without pulling the engine

-greg