A/T>M/T 1g GSX swap?

Myslow420a · Oct 14, 2012

Hey guys. I recently picked up a pretty clean 1990 GSX AWD shell from this cool guy in Kenosha. I have plans on a total rebuild on it, not quite sure of what kinda headache I'm in for. I'm planning on doing a A/t-M/T swap but I have not found much about the procedure on the internet. I hear from some people It's not that difficult but they've never done it themselves.

So... is it possible to do? Is any custom fab needed? Should I just keep it auto?

Thanks!

pauleyman · Oct 14, 2012

If it's a 90 AWD then it has to be a 5 spd. They did not make auto AWDs in 90. That car is a 91 or it's already a 5 spd. You'll need alot of parts to convert an auto to 5spd. tcase, rear end all different. Not to mention pedals, hydraulics, etc.

Myslow420a · Oct 14, 2012

Do you think the swap is worth it? Do you know anything about auto shift kits? :confused:

pauleyman · Oct 14, 2012

No I don't think it's worth it. No I don't know anything about shift kits. Verify what this car is. Something is being misrepresented.

tkelly27 · Oct 14, 2012

If you want a fun DD, keep the MTX. If you want to drag race, keep the ATX. Over 400hp the MTX will break until you put about $2k into it, then it will break less often. The ATX can also break, but it will handle a lot more in stock format, and take slightly less money to be bulletproof. It seems that a MTX will never be bullet proof with more than 5 or 600hp.

I vote swap to the MTX, and keep the ATX in the garage for when you want to make serious power

A full line pressure shift in an ATX will make you forget about a MTX.

toofast82 · Oct 14, 2012

I did the swap about over to m/t from auto about 4-5yrs ago..
Honestly, to me the only drawback to the auto tranny is the gas mileage being worse
It launches great when done right, is consistent, potentially less drivetrain breakage from preloading on launch and you'd probably run the 1/4 better if you did everything right.
Look into some type of 100% line pressure mod such as RoadSurge shiftbox, tcu custom eprom chip or "blue wire mod"

Myslow420a · Oct 14, 2012

Thanks guys.

I dunno, I'm going to daily this car, and I'm on a budget so from what I speculate keeping the auto will be cheaper. I hear that auto's hold a ton more power with being close to stock. I think I'll just keep the auto ( I have two

) and possibly buy everything I'll need to do the swap along the way when the project is all said and done, so when I feel for a change in my life, It's all in front of my face.

I can't really find anything helpful on google, plus I want to make it to 30 tech posts by tonight;].

What exactly is a 100% line pressure mod? Something to do with the valve body I suppose? (Sorry, don't know much about the guts in the ATX)

toofast82 · Oct 14, 2012

100% line pressure mods will give you very firm and quick shifts. There's some vids on the roadsurge box to give you an idea of how it works. That uses a box with an up/down that you'll use under wot conditions to shift the trans. Bluewire mod will use the stock shifter to shift. You can have it activated by a switch to shift normal under cruising conditions or switch it over to 100% line pressure shifts.
Custom eprom tcu chip id imagine will go off your tps% and adjust to 100% at wot and normal under cruising

sniver · Oct 14, 2012

I've had both the road surge box in an auto, and swapped to a 5pd after. It is no easy task changing out the pedal assembly and making a hole for the slave the the engine in the car. Also have to make a hole for the shift cables, also nearly impossible with the motor in.

After that I hope you plan on leaving the auto harness in the car because the body -> engine harness connectors are different, and it's easier to splice some wires for the reverse lights. Also atx and mtx starter harness have diff plugs in 91+.

The rest is mechanical and easy. If you are serious, do the pedals first, because that's the make or break part.

I regret the swap in part do to longevity and cost of repair. You will sh!t a clutch or two, and at least a trans for the life of the atx. However a push button box is not for me. 5spd is my opinion for a dd, but if I were to make a track car I would go atx.

My first hurdle with an auto would be getting rid of that midget turbo. 13g's make me sad.

toofast82 · Oct 15, 2012

sniver said:
I've had both the road surge box in an auto, and swapped to a 5pd after. It is no easy task changing out the pedal assembly and making a hole for the slave the the engine in the car. Also have to make a hole for the shift cables, also nearly impossible with the motor in.

After that I hope you plan on leaving the auto harness in the car because the body -> engine harness connectors are different, and it's easier to splice some wires for the reverse lights. Also atx and mtx starter harness have diff plugs in 91+.

The rest is mechanical and easy. If you are serious, do the pedals first, because that's the make or break part.

I regret the swap in part do to longevity and cost of repair. You will sh!t a clutch or two, and at least a trans for the life of the atx. However a push button box is not for me. 5spd is my opinion for a dd, but if I were to make a track car I would go atx.

My first hurdle with an auto would be getting rid of that midget turbo. 13g's make me sad.

The pedal assembly definitely isn't fun haha. Making a hole for shift cables and master wasn't bad at all with engine in car. I didn't swap starter harness or starters and the car was 91.

Myslow420a · Oct 15, 2012

So should the MT bolt up right into my car? Don't I also have to change the the front and rear end?

tkelly27 · Oct 15, 2012

Atx and mtx have different differential ratios and different transfer cases. Everything else is a bolt in.

sniver · Oct 15, 2012

Vfaq.com > drive train > at/mt swap. A nice write up for the fwd. All you have to add is a rear diff and xfer to the list.

Myslow420a · Oct 15, 2012

sniver said:
Vfaq.com > drive train > at/mt swap. A nice write up for the fwd. All you have to add is a rear diff and xfer to the list.

Oh wow, this is gold. Thanks!

I can't waiiiiiiit to start building. Although I am still juggling ATX/MTX. Both have their good/bad. I think for now I'm going to stick with the auto and build it a little. And down the road I'll piece together what I'll need for a swap for the future. Any recommendations on a good trans shop that does a lot of DSM's? I hear quite a bit of Shepardtrans. Any opinions?

Metal Health · Oct 16, 2012

Buy a spare trans, chilton book, vfaq and build the trans your self. study the spare inside an out.

The Top DSM Community on the Web

A/T>M/T 1g GSX swap?

Myslow420a

pauleyman

Myslow420a

pauleyman

tkelly27

toofast82

Myslow420a

toofast82

sniver

toofast82

Myslow420a

tkelly27

sniver

Myslow420a

Metal Health

Similar threads

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds