I just installed a new tranny, and vig. converter in my 00c5. drove for a week, then went to the track a week ago. made 3 passes total. second pass when I was slowing for the return lane, I heard a noise like a swishing noise from under the car by the shifter I think? Now when I drive normal there is a slight vibration above 55 to about 75. but when accelerating 2/3 throttle, It vibrates the seat,floor pretty good. If I hit it full throttle, is goes away?
I checked the converter bolts again, balancer bolt, changed d.r. to street tires. So far, 3 poeple have told me to take torque tube apart and check the couplers and center support. any other input the same, or other things to check.
thanks Nuzz

 

Tranny mount. Mine did the same thing. Builders usually forget to replace and reuse the old one. Took it back to my builder and found that the tranny mount was torn up. Replaced it and there is a slight vibration but not as bad as it was before. It felt like my tranny was going to fall off.

 

Yeah mine was doing that after i had Some tranny work done. So i jacked it up and i could take all the Bell housing bolts out nice huh? Lock tighted them Blue and hasn't happend again been to track few times to