i had my 350z for 4years now and haven't had this problem until 2007.
When i try to gear up 2nd to 3rd it crack little bit. it sounds like metal is grinding. But the thing is when i drive slow meaning shift 2nd to 3rd slow, then it's fine, it only happens when i try to shift fast. What is wrong with my gear?? please help me out thank you....^^

 

i used to have the same problem, but that went away after i change the clutch and flywheel.

 

mine just started doing the same thing yesterday and bad today. im so pissed because ive never had a problem. now im scarred i have to change my tranny. i just broke 40,000.

 

60k drivetrain warranty on most 350z

 

take it in to nissan and have them change out the tranny.