When I have a truck full, and Im slowing down I get a short humm or vibration is this coming from the u-joint. This is the only time it happens , should I be concerned. I have a 2001 GMC 2500HD crew cab Duramax THANKS J.L.:help:

If you have a short bed there is a TSB to replace the 2 piece shaft with a one piece to prevent shudder...If you have a long bed you are SOL.