I have a 2006 G35 coupe automatic with 69500 miles on it and it will not go into reverse when the car is warmed up. It seems to engage reluctantly, but hard if it's the first gear selection in the morning or when I leave for work 9 hours later. Once the car is warmed up, no reverse at all. Sometimes it pulses like it's trying. Last Friday, when leaving for work, I was able to get reverse to engage and then went backwards for a while in the parking lot, maybe hitting 15 mph. Then it wouldn't go into Drive very well after that. It seems to buck a little like it's trying but no full engagement. I put it in neutral for about 10 seconds, tried drive again and it was ok. I've taken it to Infiniti of Syracuse and they acknowledge the issue but say they cannot find anything wrong. They did a drain and fill to "see if it would help." Well, it hasn't done much of anything to improve the situation. I've searched and searched through this forum, Z forums and infinitihelp forums. Someone has had to have this happen before...I just can't find the solution anywhere. Has anybody dealt with this before???

Can you just take a valvebody out of one car and put it in another???

Do I have pressure problems???

I have had the car serviced at a Nissan dealership and they have never recommended a trans service, so it's the original fluid at this mileage. I have driven the car very easy. Just to give you an idea, all the rotors are original and the front pads are too. The rears were replaced around 55k. Either way, should I do another drain and fill in 500 miles or so???

 

If changing the fluid didn't do anything the first time, no reason to think it would help now.

And really, the only way an issue like this would be caused by the fluid is if your fluid was extremely low.

You need to figure out if it's a computer issue or mechanical.

You could try resetting the ECU.