Hey everyone hoping to get some advice on an issue im having, the car is a 2004 track with 100,000km.

Im currently having a grind issue that only happens sometimes when shifting from 1st to 2nd fast and at high rpm, the car won't go into 2nd and just grinds loudly, kinda like shifting without the clutch. When driving normally or shifting slower this doesn't happen and feels pretty smooth, any help would be great

 

Welcome- when was the last time you drained and filled your tranny? What type of lubricant did you use?

 

Im unsure of the last time its been changed, however all the other gears shift really nicely and dont grind at all

 

(RPM match and no grind) + (No RPM match and grind) = Bad Synchro

 

the grinding never happens when downshifting into second even when not rev matching, only shifting from 1st to 2nd

 

At 100K, if you haven't yet changed the tranny fluid, it's overdue. A fast upshift from first to second gear relies upon a double cone syncro that can get worn. Before doing anything else, I'd suggest a change to Redline MT85. It's an advanced synthetic GL-4 gearbox lubricant that meets Nissan specs and has enough friction engineered in to allow the syncros to function properly.