Over the holiday I was pulling my camper across the mountain. On the way down, the transmission geared down two gears instead of one. This put the RPM's at about 4,000. It did this a couple of times. This is the first time it has done that with me. Usually only gears down one gear. Has this happened to anyone else?

Just happen to me when comming down the east side of Washington pass (north cascades, Wa St.) towing 3500 lbs tent trailer. The grade is fairly steep, applied the brakes and it downshifts x2, rpms up to 3800 and the wife starts asking questions and I'm tryin to watch gauges, the road and understand what the truck is doing. I have read here that it's ok to have high rpms on the downshifts.

That is normal and typical, although a bit unnerving. I have 55k on my '02, and it has done that on every big hill since new with no ill effect.

no biggie.

It is no big deal, I was dragging a car on a trailer across the Great Divide last week in T/H. On the 6-8% grades it punched down 2 gears and the engine was whining in the 4K range too. Allison says this is normal and GM says the Duramax is built to withstand 4K rpm...the noise with the fan engaged is a little unsetteling...just pop out of T/H and it will pop up a gear...uses your brakes a little more but you really should not have a problem doing this.