okay heres the deal most of the time when my car heats up and i'm driving it down the road shifiting gears from first to second i have no problem but as soon as i hit third around 3500 rpm my gear grinds and every time i down shift for 5th to 3rd it always grinds before going in. Is it a transmission problem? or just my gear? or gear box? car is 93 gs-r