I have a 2001 Integra GS-R that only has 62,000 miles on it and 5th gear keeps popping out. The problem only seems to occur after driving on the highway about 20 miles in 5th. But once it starts to pop out and keeps happening every 20-30 seconds. I was wondering if anyone had any idea what type of problem this could be (synchro, fork, etc) and about how much it could cost to fix.