Problems with 2005 GMC Sierra 3500 ENGINE AND ENGINE COOLING

Gmc 3500 crew cab dually with the 6.6 duramax diesel and allison automatic can to perform its designed job with out over heating. truck is rated for 23,500 gcwr and a 16000 towing capacity. however it struggles to pull 7000 pounds and engine temperature got over 230, and transmission temperature over 210. the cooling fan struggles to control the heat and runs constantly, the noise is unbearable. if one were to attempt to pull my rv up a mountain grade in the summer i would be left stranded on the road or in traffic. *nm

I have a gmc pickup truck with a diesel engine that has a chronic overheating issue. i am not the only one with such an issue, as there are literally hundreds, maybe even thousands with this problem. this issue is exclusive to gm diesel pickups with the 6.6 liter duramax diesel engine model year 2004.5 and 2005. i have had my truck for only 2 months and am taking it to the dealer for the second time. i have read that gm has had to buy back several of these vehicles. while some dealers across the country are recognizing the problem and telling customers that gm is aware of the problem, many are denying any documented service bulletins or that a problem even exists. this problem is predominant when towing and hauling, which is what these vehicles are designed for. i purchased my vehicle specifically to tow a travel trailer with. i can't do that without having an engine overheating issue. the potential danger of towing a trailer and your vehicle overheating is quite obvious. my dealer told me that there was no problem found when they tested my vehicle. they could not simulate the situation causing an overheat. the best they could do was get the truck to heat up to 230 degrees, which by the way is about 15 degrees over normal operating temps. i am taking my vehicle back to my dealer for another check. do i have to be stranded on the side of the road potentially endangering my life and the lives of several motorists before general motors does something? *nm