So last week i got the TRANSGO installed on my 2007 G35 AT , with 67k miles on it.
I got to watch the tech do the install , everything looked to be going smoothly. He drained the pan , then unbolted everything , and then took the valve body out.

After he started taking the valve body apart, and adding in the new springs/valves.
Then he drilled some new holes on one of the plates , and started puting everything back together. Ok you get the point , he did the install , i went for a walk since i was sitting there for like 5 hours. So he started filling it up and were about to go for a drive , and it doesnt reverse . Like at all. He tried to rev it to 3k rpm , and still nothing.

All Drive gears work fine, but it definitely feels like its in Limp mode , the rpms feel way lower than they normally did , but it still drives forward. The shift kit feels nice too , ive already invested 300 into the kit .

SO this past week first i took it to a transmission shop , and he didnt want to drop the pan since he wasnt to familiar with the valve body and said i should take it to infiniti or nissan to get it reprogrammed(He asked around and thats the best he good do)

I took it to the nissan dealer , and asked for a diagonsis , and ask if he could reflash or reprogram the new valve body. The manager said they do not do reflashes or there is nothing they can do to reflash the trans ??? SO im kind of in a loop right now.

I saw a thread of here stating this, When you connect a different transmission up to the TCM like you did you will need to take it to the dealership and ask them to flash the EEPROM on the Valve Body. EEPROM is only written to 1 time and that is at first startup. So when you change transmission your TCM is looking for the valve body from the previous trans.

Have them flash the Valve Body and the TCM and you should be good to go.

Which i think it applies to my situation ? The guy that installed the shift kit has done 8 other installs and said this one was the only one that did this Guess thats life.

Anyways im trying to figure out the probably cause , because nissan wanted me to just replace the whole valve body which would be $1500 and labor $500 and truely think i just need a reflash . Any thougghts ?

I've looked at a couple of the TrandGo installs on the internet and none stated a need to reflash anything. Either something was done wrong or something was not connected properly within the transmission during the install.

Keep looking around, maybe I'm wrong.