I have a mustang GT 07 with 62k miles. When its cold everythings fine and it runs smooth. But once i have been driving it for about 20 minutes and im depressing the clutch when starting out in 1st gear it jerks and i can hear a thumpy clicky sound coming from where the tranny is. Also when i shift into second i can hear the thump too. When im driving in 1st/2nd, and im at about 3k RPM and i press the clutch in then depress it, feels like the transmission shakes and i hear the the clicky sound. Its weird because it only does it when its warmed up and driven. I also hear a whiny noise when i drive it in 1st. Sometimes it will even shake and jerk for a while when i take off in 1st gear. Im not forcing it at all or anything. What could this be? Please help! Much appreciated!!