Yes for what its worth my Challenger still has the problem. I haven't seen this question asked. What happens if it is put into nuetral above the vibration speed and is allowed to coast back down thru the vibration speed? Mine still shakes regardless if its in neutral or the clutch is disengaged. I was going to try engine off in neutral so the counter shaft and input shaft would not spin. The car is currently in storage.
An engine vibration doesn't have to have the vehicle moving to show up. That would eliminate from the convertor forward if it does not happen with the car at rest. Did I miss something? also when I installed a 2.76 chuck the vibration speed went over 100 mph.
Doug