1994 Acura Integra

I have had problems with my transmission for the last three weeks now. My question is. What would make my 5th gear pop out and go into nuetral? At no matter what speed I go it stays in for for however long it wants to. And I have also noticed that sometimes just before it pops out of gear, the transmission feels like it bounces and kinda shakes my car. So if you could please give me as much information as u can that would be very appreciated. If u could send a copy of the answer to this email address also it would be great. Hooverb@lsd43. Navy. Mil

V/R
Bryan Hoover