Manual to automatic transmission swap

[conedodger]

I'm just doing a little intelligence gathering here. I have not decided to actually do this. If you have the parts I need though, please PM me or speak up.

My wife loves to ride in my Porsche 914 and 911. She sits there quietly and looks serenely happy. I ask her if she wants to learn to drive them and she says yes but when I actually take her to a parking lot to teach her, no way!

The Z is different though. She calls the 914 and 911 cute but when I pull the Z out she calls it sexy in a voice that lets me know, she is not kidding. Now some of us are lucky enough to have our wives or girlfriends share our love of cars. I am not one of these lucky ones. She likes to ride in them and especially likes to ride in the 914 on the track and autocross course. I would love for her to actually drive. This has me pondering the possibilities. I know I can teach her to drive a manual transmission without causing a divorce but it will be very stressful for her and she will not enjoy driving on the street with other cars. What if I put an automatic transmission in it? I know most go the other way and take out the automatic and a lot pull the 4 speed for the 5 speed. What would be needed to go the other way? Is it impractical due to wiring harness differences? I know there are some wiring differences due to ignition safety systems and such.

I have had an automatic transmission Z. I had a 76 with an automatic and was surprised to discover it was a total autocross weapon. Just drop it in first and take off. Shift to second if you have to. Only problem ever, was that it didn't want to shift back out of second if you needed to.

What do you think? I would love for her to love to drive this car.

[Montezuma]

I got a deal for u in san diego, I have a 72 automatic that the owner wants to make a 5sp, I have everything to make the change except the pedal box. I don't need anything in return except a pedal box. You are welcome to come to san diego to remove and fetch the tranny and flywheel. I got a guy we can pay to remove it for you. The car is located on a military base hobbyshop. PM me if you are interested.

[conedodger]

I am interested but I cannot envision having the time to come to San Diego anytime soon. I wonder about the wiring harness. I know I need a different radiator, mine is an aftermarket aluminum job. What else do I need?

[Montezuma]

I know...I too am very busy. I got a guy who hangs around the hobbyshop looking for work who can have remove the tranny and ship it to you. I believe the radiators have the the auto tranny cooling feeds blocked off on manual cars, but your radiator not beiing stock could be a problem. If the wiring harness is different u can have the one that is in the car. You would have to pay the handyman to remove all that stuff for you. My 73Z is an automatic and I like it, gets 30 mpg on the freeway.

[Arne]

Most of the wiring harness differences can be ignored. You will need to splice the trigger wire for the starter solenoid into the neutral-safety switch. I can't recall anything else that should be a show-stopper.

[sblake01]

You'll also have to hook up the downshift solenold. I'm not sure if they run off the gas pedal or the linkage somewhere.

[Arne]

You'll also have to hook up the downshift solenold. I'm not sure if they run off the gas pedal or the linkage somewhere.

Oops! I forgot that. On my '71 I think it was on the gas pedal.

[Diseazd]

Montezuma......I believe the pedal box is the same for the auto's and manuals.......I'm getting ready to convert from auto to manual on my 73 and it looks like all I need to do is bolt in the 2 manual pedals into the pedal box in the auto car ( with the robbed pedals, bushings and springs). Is that right or not Arnie? Guy

[conedodger]

Thanks guys. I knew there would be a neutral safety switch but I forgot about the downshift solenoid.

She is getting pretty excited. I installed most of the new interior today. She kept coming out and looking and was finally calling it "my car" which is cool... I screwed up a couple things. For instance, you have to install the rear side vinyl before the quarter window and rear finisher. OOoops. Oh well, take it out, do it again.

[ozconnection]

Get yourself some transmission hose and rig up a cooler in front of your radiator. It's a snap really.

Just make sure that your cooler is very close to your radiator without an air gap between the two. Doing this will force frontal air to go through the cooler and not around it.

[Arne]

Montezuma......I believe the pedal box is the same for the auto's and manuals.......I'm getting ready to convert from auto to manual on my 73 and it looks like all I need to do is bolt in the 2 manual pedals into the pedal box in the auto car ( with the robbed pedals, bushings and springs). Is that right or not Arnie? Guy

I had to change the pedal box on my yellow car, but only because the PO buggered it up in it's past life. As far as I know, the pedal boxes for any given year are the same for either transmission type. Going from manual to auto should be simpler than the other way, as you will only need to replace the brake pedal, and remove all the clutch stuff. You'll want to fab a sealing plate for the clutch master hole, but that'll be simple.

Beandip just swapped from auto to a 5 speed in his '73 a couple of months ago, his transmission was suspect, but he may still have some of the requisite parts.

Edited June 14, 2010 by Arne

[70 Cam Guy]

My old Camaro was an automatic with an original style radiator. When I replaced the radiator with a Griffin unit, I added a B&M oil cooler and plumbed the lines to it. You should be fine with a similar setup. If I recall, the applications were based on horsepower, but it has been a few years