Ok so I went to go eat at jack in the crack everything was working fine except when I was about to park the car the clutch felt kind of stiff. Then I finished eating tried put it in reverse and the gears didnt want to go in. I sat there for awhile trying to put it in gear and it seems that my gears go in when the car is off but when the car is on it locks and no gears go in. What could it be? I have a 99 civic ex, the only transmission problem I knew it had was that the input shaft bearing needed to be changed.

 

could be ur clutch not disengaging, but then itll just grind any grinding