Need answer ASAP quick question on 04+ trans compatibility

[fst]

a buddy has an 04 base GT L26 and his trans is on its last leg. it wouldnt shift into 2nd gear until 110+ degree and the fluid color's burnt. he found a 04 trans from the JY but is from the L32. can he swap it directly w/o pcm tuning or is the gear ratios and/or cooler lines different? appreciate your help!

[RivMan]

Gear ratios ARE different.

Trans lines MAY be different

Valve body MAY be different if it came from a Comp G car

Torque Converter I believe is different

-Rob

[fst]

If the tc is different then i imagine so is the flex plate

[BillBoost37]

Flex on most 04's are dual drilled, so no worries.

[Below Average Joe]

Here is my flex on stock 05 gt n/a

[fst]

so it looks like just gear ratio is the only issue correct? if so, can the powertuner tune 04 to adjust the gear ratio? and if so then it's doable? assuming the cooler lines are also the same.

[91parkave]

04 and up should all be the same With no check valves in the fittings

[RivMan]

Yes, you should be able to correct the PCM with a DHP Powertuner. (That's what I used on mine)

Not all 04+ cars had the same checkball setup. My 04 GT (Original Trans) had a trans with the checkball in the valve body, but my donor car (04 CompG with a SeRTA Trans) had the check ball in the fitting.

Make sure the trans he's getting isn't out of a CompG car (Tap Shift Transmission) as the valve body and channel plates are different and incompatible.

-Rob

[fst]

coolbeans, appreciate all of your help guys. worse case is he buys the entire motor, trans, pcm, and wiring harness.

[RivMan]

If he's going that route, grab the fuse box and ABS module as well. They are different between the 04 GT, 04 GTP, and 04 CompG.

I would only recommend it if the car is a Non-CompG though, there are more changes required if you want to swap over to a CompG drivetrain.

I did basically the same thing in my car.

-Rob

[fst]

He'll know once he goes to check it out more thorough.