I'm frustrated! 05 C6 A4 bought 4 months ago with 3-4 band burnt I R&R'd the tranny, replaced the guibos and bearings in the T.T. while at it! The rear guibo was shredded pretty badly. I now have the T.T. rumble :-( , Using a long screwdriver to the ear you can definitely tell the clicking rumble is coming from the rear bearing area. It only does it at idle & doesn't matter if in P.R.N or D, raise the rpm a 100 rpm and all is quiet. I just pulled it all down again, I found that the the big input nut was only at about 40 ft.lbs. so I torqued it to 93 lbs and the corresponding hub that houses the 2 rear bearings felt tighter (less play but rolled very smoothly) I reassembled the torque tube put on stands and spun it up with a drill. It still made some noises at the same area, so I put in 2 new bearings and that didn't change a thing, The run out of the shaft is minimal! The bearings and shaft roll freely and feel fantastic. Any ideas guys and gals?
thanks

 

And I really thought Ford was crazy for using giubos on its Transits. I had no idea that the Corvette was using them. Having a rag joint in a drivetrain just seems like a very bad idea. I wonder if the C6 and C7 used them.

FWIW, I noticed that a few Transit owners are complaining about some type of rumble before the giubo joints go bad.

 

The rumble was from the Large nut on the rear of the TT. (holds 2 flanges in the bearing housing) Not being torqued tight enough!

 

Thanks for the update. Might help somebody in the future looking for this problem. Probably a good thing that you found it when you did as it would have probably caused some serious damage had you not.