Hello. I recently purchased a Chevy Silverado 2500HD 4WD after much looking, researching, and consideration. I bought it to pull my 30 ft. travel trailer, which I just took on the road for the first time. There are a few things that I noticed and looking for some input. 1) While pulling the trailer, and placing the truck in tow haul, I could not really tell the difference between pulling with it on or off. My RPMs ranged from 2.5 to almost 4, but mostly around 3.5 and the transmission temp kept going over 200. The highest temp was 208. I pulled over until it cooled some. Is this normal? Is there something I can do to reduce the RPMs and trans temp? 2) This is a general question. I've noticed a strong vibration and even a shaking at times at/above 60 mph. It can be felt on the steering wheel, floor boards, seats, basically all over the truck. Could this be tires out of balance or something worse? I appreciate any input and thank you!

 

The transmission temperature you're seeing is normal. Dexron VI only starts to break down above 250° F. The DIC will give you a warning, "Tranmssion hot. Idle engine" if the temps get too high. I've pulled my 7,000-lb travel trailer all over the Rockies - Yellowstone, Grand Canyon, Moab, Colorado, etc. - and have had it as high as 235° with no warning messages. Don't worry about it.

The 6.0 motor likes to rev. The torque peak is over 4,000 RPMs. Notice how there's no redline on your tach? That's because the engine can rev to 6,000 RPMs without any problems.

On our last trip out West, our gross weight was 15,000 lbs, and we were on I-70 approaching the Eisenhower Tunnel (11,100 ft). The engine seemed to be in its sweet spot at 4,000 RPM. Here's a pic of my gauges during this pull:


Regards to the vibration - yes, I would start by having your tires rebalanced. That's the most likely culprit.