I had the tow mode on and was doing 30 MPH.If I just coast with little throttle there is a growling vibration that can be felt. If I turn the tow mode off the vibration goes away. Is this normal? Or could the TC be bad?
Anybody else notice this? 12,000 miles.
The truck is stock by the way.
2005 Auto with 3.73 gears.

 

On my '06 @ 28(tow/haul), 38(O/D off), 48(regular) is w/ the TC locks up. I have had the groaning/vib. prob. @ TC lockup & is in the shop for it now. They are telling me that since the exhaust hanger attaches to the bellhousing, when the TC locks up, it makes the hanger/exhaust vibrate right there. I am picking it up in the morn. & I am gonna have them put it on the rack to prove it to me 'cause I don't think that's what the prob. is. Thay said last dealership that worked on it bent the hange r& that's why it does it now & didn't do it before. I'll try to keep you posted on the results. HTH.