I purchased a 04 350Z 6 Spd. with approx. 40,000 miles. and took it out today to play with and realized that its hard to shift into all gears but 5th, and a burnt rubber smell was coming from around the trans. I have no clue where to begin, and have only ever worked on hondas. someone help, this is a car for my g.f for her birthday

 

Well from the smell one would assume the clutch is not disengaging completely. This car is known for its insistence that you push the clutch pedal down all the way. If that isnt your problem, you are having some sort of issue with the clutch hydraulics... Check that.

Any grinds?

 

grinds into all gears at both high and low rpms. replaced clutch and mechanic states same problem as before. ive read about all the problems with the 03/04 trans but i made sure i engaged the clutch all the way before attempting to shift...im lost

 

If you're shifting correctly and the clutch/pressure plate is new, then the problem is most likely with the hydraulic system as SpoilsofWar said earlier. If it's grinding then the clutch is not disengaging completely and I would guess a faulty slave cylinder or master cylinder.

 

ok ill check the hydraulics system tonight and let yall know in the morning, thanks for the help.