It is possible to do a transmission Swap from a 2006 Coupe G35 AT into a 2005 Coupe G35 AT? I was told the engine would be no problem but not the tranny due to differences inside. Is this true, is there really a difference being only one year apart? Both are DEs. Please help me out!

p.s: I have the ecu, bcm and harness if it helps with the swap from the 2006...if that changes anything.

 

It will swap in directly, nothing needs to be changed. The 2004.5+ to 2007 coupe 5AT is basically all the same. Only thing that changed was some minor revision to components but overall it's the same RE5R05A with the single large harness plug. You shouldn't even need to swap out the internal TCM, it should talk directly to the ECM.

Parts interchange catalogues will say it's not compatible, this is only because the ID tag is different, across 2003-2008 RE5R05A transmissions there are like 14 different tags due to sourcing solenoids, bushings, clutch disks, etc from different manufacturers. At the end of the day though there are only two different RE5 for this car, one with the single large harness plug, and one with THREE smaller harness plugs.

You can even swap the harness between the two. The single large plug has the TCM mounted internal with the transmission, the three small harness (two green and one black iirc) the TCM is mounted in the cabin next to the ECM. You can use ANY of them as a donor if you swap the existing valve body+TCM (which includes the wire harness) into the donor transmission.

If you get the one with the correct plug to begin with then you don't need to swap anything.

A TCM only needs to be programmed if it's BRAND NEW, a used TCM is plug and play for the car. It doesn't require any Consult-II/III pairing with the ECM/BCM.

EDIT: Keep your existing ECM/BCM. I wouldn't swap those out unless something was wrong with them.

 

Thank you so much for your response and time to answer my question! Makes me feel a whole lot better about the swap. I have one more thought, you said I should keep the existing ECM. I plan to use the ECM from the 2006 (donor car) because it will have NATS deleted and a tune ready for all my bolt ons. I'm doing this so there's minimal chance of the transmission not pairing with the ECM. What do you think in my idea?

Thanks again Cleric670

 

If you're doing an ECM swap then you also need the BCM. They need to be the same MEC number as the ones that are currently in your car.

I strongly recommend doing these swaps separately, transmission, then the computers.

I also don't recommend running a tune that was for a different vehicle At least you will already have a license on the ECM so it would be easier to get a retune. It's an UpRev tune on that donor ECM yes?