ok i have been dealing with this vibration problem for a while now. Its a 97 ta m6 here is a list of everything i have done to it new trans mount,flywheel,clutch,rebuilt t56, and a new pilot bearing.The motor only has 32,xxx miles since rebuilt and now i'm completely out of ideas. it all started after my clutch messed up. i went to turn it on and it didnt. i tried again and it did but when i would press the clutch it wouldnt disengauge. When i got home i turned it off and tried again but nothing so my unlce wanted to push start it and it worked but made a horrible noise. so i pulled the tranny when i did the clutch fork wouldnt move back and i had to move my tranny side to side when i got the tranny off the clutch fork had broke off of the bolt that holds it in place and got jammed some how. once i got the tranny off there was alot of metal shaving in the bellhousing of the tranny. now that you know what happened. i guess what im really wanting to know is did i mess up the motor i have changed everything i can think of to fix the problem.the car vibrates at idle not bad but there. when i am driving i get get it up to about 2900-4500 rpm its bad i can feel it in the shifter. it kinda feels more toward the back its really noticeable in 3rd and 4th. i can put it in neutral and rev it and its fine no crazy vibration. i have not changed the u joint out. does the lt1 have some vibration? and can exhaust cause it to vibrate at idle? im out of ideas and need help sorry for the long story