When I drive my third gear grinds in even with clutch pressed to the ground. It also happens to fifth once in awhile and pops out of gear for fifth only. This happens to it when the car warms up if I drive it cold it won't happen only when engine warms up. And it only happens in 3rd and 5th. Others are great. I checked tranny fluid and it's good and full. What could the problem be? Could it be the pressure plate or is it the syncros? Please help.

 

The fluid could be incorrect. Replace with genuine Honda MTF and see if that makes a difference.

The shift lever popping out of gear is more worrying. That usually means the dog teeth are worn out on that gearset.

 

I do use Genuine Honda MTF. I will check on the gear though cause it didn't look to good when I got it I just needed a drivable tranny fast. Thanks for the help.