Very Weird Transmission Issue
 

So I have a 2011 370z nismo, only mainly driven on weekends, spirited driving here and there. But over the weekend I was doing a couple pulls with my buddy in sport mode and it locked me out of 5th and 6th gear and popped up yellow triangle for s-mode and wasn't showing any gear indicators on the dash, so I turned it off and turned it back on, everything went back to normal, now here's the weird part, it will go 1st-4th gear smooth no problem, then when going to 5th or 6th it will go in smooth and show on dash it's in either of those gears but will act like its in neutral and not actually engage the gear. But if your at a dead stop and try 5th or 6th gear it will engage it and pull the drivetain. I'm 81 miles over my warranty and the dealership isn't liking that so looking for any help.

Yikes. That is a weird one. Well, hello from Morrisville.

That's not good. It is as if the shift fork for 5th and 6th has an issue or you have a counter shaft nut that has backed off causing the issue. The older 280z and 280zx trannies would do this. Most of the time it would destroy the tranny in the process because the nut would fall into the gears.

How many miles on the car? Powertrain warranty should cover it.

I was thinking shift fork, but have encountered a shift fork issue before and it wouldn't go in smoothly at a stop or rolling

I'm at 60,081 but the car is also Greddy twin turboed

Ugg, your done. You can see if they can fix yours. If not your in for a tranny.

Im going to take it up to the stealership this week and have them diagnose it if it turns out to be tranny, im going to pull it myself and replace with one my buddy has out of his 2010.

Before taking it to the dealer, I'd get an OBD/CAN scanner and see if any DTCs have been thrown. It's a long shot but you can borrow a scanner at most auto parts stores so nothing to lose.

like SouthArk370z said, get a reader and get the code.

But it does not sound good.

With only 81 miles over, there's a good chance your Nissan dealer goodwill the warranty. However, now I see you have a turbo. I can see the dealer making a connection between the turbo and your tranny going out.