01-12-11, 10:58 AM
I have an 05 cts-v 45,000 miles on it just bought it a week ago and i have this vibration everyone has talked about. i cant quite nail it down to any exact symptom. in 6th gear i feel the vibration anywhere from 45-90, the trick is i do not feel it in the shifter what so ever and it only occurs on absolute decel ( when the engine is in braking mode and right in between coast and accel/ very light throttle) if you put torque/throttle to it it goes away. everything looks and feels good underneath. any thoughts?? ps there does almost seem to be excess play in the drivetrain (rear diff) not sure if the clunk is normal for sure or not, i do expect some being a manual transmission and all but out of curiosity...
Is it only in 6th at those speeds? 5th has no vibration? Yes there should be some play in the drivetrain and yes the clunk is normal. From what I've learned here I can tell you that there have been a number of case of 6th gear vibration caused by lugging the engine in 6th gear under 50mph. I would make sure it's 6th only first and go from there.
01-12-11, 12:38 PM
5th no vibration, only 6th. and the lugging engine i can feel the harmonics, but this is a definite vibration on really light load and and coast basically like i explained before.
Any noise associated with it? Is it similar to a wheel out of balance type of vibration? If it's only 6th gear I haven't heard of anything other than possible damage to the transmission but don't freak out I'm just parroting here. I personally haven't had any experience with the 6th gear vibes so hopefully someone else can chime in with a better explanation/suggestion.
01-12-11, 01:39 PM
definitely a high speed vibration as in transmission drive line or rear components
01-12-11, 02:03 PM
I know these driveshafts are designed differently now, but with the conventional one-piece drivshaft with U-joints, vibration on decel only was the signature of a failing U-joint.
This is very similar to what I experienced. It peaked at about 65-70mph, only in 6th gear, sort of barely coasting at that speed. There's a thread devoted to this on here somewhere. After checking the diff, driveshaft, and several other things, the dealer settled on the transmission and gave me a new one. That solved it completely. Until then, I had thought it was something I'd just have to live with. I hope you have a warranty! Has the dealer checked it yet?