Chuck, I pull a 24' Car hauler with a GX460 Luxes inside. Total Weight around 10K. When I started pulling the trailer with the car inside my transmission oil temp went up by 20-25 degrees. In the mountains it would jump up as high as 30-35 above normal. Had the transmission serviced and the temp drop back to what it was when I was just pulling a F150 four door truck. When the transmission was running hot it pushed up the engine temp also by about 10 degrees. So long story short you may want to find out the last time the transmission fluid was changed. And if you can't find out it can not hurt to have it changed. At the last rally in OKC we had a great seminar at United Engines and it really opened my eyes on transmission issues. The new TranSynd fluid can make a hugh difference in heat and performance.

GAry