I have a new Silverado 2500HD with the DMAX / Allison combination. The truck has a little over 5K miles on it now. The transmission has done something pecular a few times. I'll be driving down the highway at about 70 mph, and coming up to a red light so I start coasting up to the light. I get down to about 35 mph and a couple hundred feet from the light when the light turns green. I hit the gas (or is it called hitting the diesel ):h ) and the transmission goes "zzzzzz_clunk" as though there were a lot of slack in something that had to be taken up before the drive could be re engaged. There is a split second pause when it feels like I'm in neutral and then bang into drive. This has only happened maybe three times but I'm not sure what to do about it. The trans oil level is fine and I did change the spin on filter at 5K miles. I'm sure if I brought it in to the dealer, they would send m away with the "unable to duplicate problem" Any thoughts? Thanks.

I can be going just 20 or 30 mph, let off the gas, then hit the gas and there,s a split second pause and then cluck. I hope the warrenty will fix it

It's probably a 5-3 skip downshift. If you have only done a few it's likely not dialed itself in yet. Do a few more and it should firm up.