Transmission Clunk

do u heard the noise, or feel the car have a little travel to the front, when u put the clutch in ?

If your car has the T3650 tranny then yeah its a VERY common issue. I do the same thing at red lights and when I pop it back into 1st the is a slight clunk/thud as it engages. You may also notice it when downshifting into second sometimes. Nothing to worry about according to Ford and Tremec its a "normal" noise for this transmission. Some say its better than the T-45 because its a more heavy duty tranny but it can be noisy as hell. All Ford suggests is to change the transmission fluid. Tremec suggests certain fill levels or brands of fluid. Both of which seem to escape me at the moment but Im sure someone else can add to what I said here. If you drive your car in cold weather you also may notice the second gear clash and/or the same clunk noise when you push your clutch in. All common characteristics of the T3650 and dubbed "normal" by almost everyone. No need to worry as I have had this noise for the past 40,000 miles and my car still runs fine. You might also want to search the forums next time since there are HUNDREDS of threads on this topic that all say the same thing. If its really annoying you though you could always turn the radio up loud or if your willing to spend the extra cash swap out the old drive shaft for an aluminum one. Althought I dont know how well that would work but I have been told by a couple people that the aluminum drive shaft makes the shifts easy and a little less noisy.