Had Transmission Rebuilt and heard a noise(My Story)
All stock driveline components on a 136K mile 99 Z28.
With the help of my good ol' dad and a friend my T56 was removed from the Z and then delivered to the shop. After getting everything buttoned back up and rolling again I heard a noise. Someone had seemingly put a card in my bicycle spoke. Didn't feel like jacking it up again(I'm kind of lazy, and didn't feel like chancing getting wrapped up in a spinning DS as i searched for the noise with the car on jackstands.) so I went back to the shop and told them. The shop kindly obliged and helped me to find the issue.
Sounded like a tick that turned into more of a buzz with increasing RPMs. Was more pronounced inside the car and sounded as though it was right where the DS met up with the rear end(or at least near that area) Though it was not entirely unsettling, any noise heard after this type of operation that wasn't there before kind of has to concern you for the simple fact that you never know if something might have inadvertantly gotten effed up as you were uninstalling and reinstalling the transmission. So, to the point, it literally sounded like a playing card in a bicycle spoke. This noise was independent of everything so long as the wheels were turning and sped up with increasing RPMs.
The Breakdown(And final Verdict)
I still have the stock u-joint at the connection between the rear and DS. These have some type of metal strap tacked onto both side of the bearings. We removed this originally thinking that it was it. Nope. Checked that the DS felt tight into the tranny and at the rear end connection. After a little further inspecting it was found to be a zip ties tale flapping against the DS as it was spinning. I believe that was put there by me during a fuel filter install maybe. Don't know either way I saw in another post that someone else encountered this. During the re-install of the TQ arm we must've inadvertantly gotten the zip tie on the wrong side. Moral of the story is simple. Cut the damn tail off of your zip ties so they don't make you believe you have a problem later down the road.