I have a 98 mustang gt with 70,000 miles on it. I had a new centerforce clutch put in like a year ago. The car runs great but the transmission is the problem. Last summer the car started grinding third gear alot. After i installed steeda's short throw shifter that went away and after awhile 4th gear started grinding. My car then went in the garage for the winter and when i got it back this summer it just keeps getting worse. If i put it in 4th and dont slowly and i mean slowly let off the clutch it will pop out of gear. And when im driving in 4th after awhile sometimes it will just jump out of gear. Further more the car will grind between almost all the gears if i try to shift to fast or when im getting on it and then shift. Is my transmission going or could it be something else in the transmission which is making this happen? 
