WHen I am on the highway my 05 duramax feels as if there is some play in teh rearend. Is this normal? It happens when you let off the gas and then give it more. It kinda jerks. Any one noticed this or is this just the low gearing at highway speeds? THanks for your thoughts.

I checked u joints they are good

tranny mount is good

the rearend had a little slop in it, but nothing bad when I puled the driveshaft off. I turned the rearend back adn forth.

some lash in the driveline is normal, and you may feel that by driving it that way.

I got the same thing, I figure its normal. it's not a cluck or anything major, just a soft bump