Gearbox or clutch issue
 

Hi,


I've got an '04 blob eye WRX with 90,000 on the clock.


It's running a stage 1, around 270 bhp.


As far as I'm aware it's never had a clutch.


When I change from 3rd to 4th and 4th to 5th at anything over 3500 rpm it crunches or grinds. Only in these gears and only above those revs.


If I double de-clutch (even at high revs) or change below that rev range then there is no problem.


There's no whining or unusual noises, the clutch doesn't slip or smell.
All other gears are fine and its only started happening in the last few days.


Does anyone know what this might be? Is it new clutch time? or could it be a gearbox issue?


Thanks

Sounds like it could be a synchro issue to me. If it was the clutch, it would have problems in all gears.

As above,synchro issue.
Try a gear oil change with some decent recommend stuff,sometimes cures the crunchy boxes.