So the new clutch is in. No more vibrations when i down shift but the car still slips in 5th gear. It grabs perfectly fine throughout the gears and then in 5th while cruising it revs up and pops back into gear without me doing anything except giving it gas because i sometimes dont react quick enough to let off the gas. what can this be? I got new clutch, pressure plate, thrust bearing and the seats for the bearing.