jdm svx trans, will it work?

[herffstyle]

I have a '92 SVX, the tranny died and i found a JDM svx trans and got it. what will i need to change to make it work. its all bolted in and ready to go but i haven't started the engine yet. i just read that the jdm wont work because of the tcm. what is different? can it be modified?

thanks
Steve

[redlightningsvx]

I think the gear ratios are differant also but don't quote me on that.

[TomsSVX]

depends, does the back end of the transmission look any different than the old one?

Tom

[oregondave]

it needs the jdm tcu as well as it being designed for AWS

[oab_au]

Yes you will need a 3.7:1 rear diff, and swap the C solenoid for the US one. Then use the US TCU.

Harvey.

[herffstyle]

Here are some pics of the trannys, the one on the jack is the JDM, the plywood is the US one.

IMG_1300.JPG

IMG_1302.JPG

IMG_1299.JPG

[oregondave]

Originally Posted by oab_au

Yes you will need a 3.7:1 rear diff, and swap the C solenoid for the US one. Then use the US TCU.

Harvey.

Should have kept my mouth shut

[herffstyle]

where can i find the 3.7:1 gears?

[1986nate]

Originally Posted by herffstyle

where can i find the 3.7:1 gears?

JDM SVX only...

[huck369]

Originally Posted by 1986nate

JDM SVX only...

Not Correct.....the XT6 automatics came with 3.70's, and use the same rear diff housing as the SVX, so you'd just need to swap in the SVX LSD unit into one.....and they can be bought cheap on USMB

[1986nate]

Originally Posted by huck369

Not Correct.....the XT6 automatics came with 3.70's, and use the same rear diff housing as the SVX, so you'd just need to swap in the SVX LSD unit into one.....and they can be bought cheap on USMB

My bad, did not realize that, Huck...

[TomsSVX]

Also the 07+ wrx uses a 3.70 rear diff in the same 5bolt sideplate r160 as us. You still need to swap the guts but thats about it

Tom

[Trevor]

Originally Posted by oab_au

Yes you will need a 3.7:1 rear diff, and swap the C solenoid for the US one. Then use the US TCU.

Harvey.

Steve, please note.

You must retain the JDM normally open solenoid as well as the JDM TCU. The US TCU might operate after a fashion, but the programming is unlikely to suite the centre diff. set up.

Fitting a US normally closed solenoid will reverse operation in respect of front rear bias. The use of different solenoids, enables the same on/off sequence for the pulse width modulation signal, to be used for both types of transmission. There is no doubt that this is sensible economical design, resulting to several areas of reduced cost, as well as a logical common set up.

[herffstyle]

I have an update,
everything is installed, tranny, rear gears with SVX LSD.
I drove the car down the road and all was well at low speed, when i needed to turn it felt strange, kinda like a 4x4 truck in 4wd on pavement. So i belive the center diff is locked or something.
I dont really know how the center diff is set up in the JDM.
I am using a US Spec TCU.

other than that it accelerates quickly and shifts nicely.

Anyone have input?
Think the JDM TCU will fix it?

Thanks
Steve

[TomsSVX]

yes

The JDM trans' center diff works on an opposite method so when the TCU commands FWD the trans will apply AWD. You will need the JDM TCU. Whether it will plug right in is the only thing I am not sure of

Tom