I have some serious transmission problems and hope you can help. My car is 05 G35 Sedan RWD auto. The car had a slight shudder (40mph going up hill with light throttle). About a year of that the car is now bumping hard into gear. Sometimes its smooth sometimes it hard. Sometimes the car seems to slip in between gear changes, rpms go up, then bam hard shift. The car has two codes for hi low clutch solenoid valve circuit and clutch valve operation. The fluid has been changed 3 times in the last 4 years.

Long story short, I think the valve body slowly went bad and with me driving it, the clutches are burnt. Fluid that's only 1 month old has already turned black.

So I have been looking for a used transmission as I cannot afford a $4000+ rebuild or re-manufactured unit. I know the 03-04 transmissions are different with external TCM. When I run a search on car-parts.com. Looks like the 05 is different from the 06 and the coupe is different from the sedan and the Z is different from both. I dont see how one could be different between 05 and 06 or sedan and coupe. The only differences between 05 and 06 is the rear differential ratio.

Can an 06 transmission go into an 05 car or a coupe transmission go into a sedan or Z? a reflash of the eprom should code it to work right?

 

I have found an 05 sedan transmission and since that is a direct swap I will probably go with that.

I am still curious as to what changed from year to year and car to car making the transmissions different. I was told the other transmission will work if I swap my internal TCU into the other transmission.