06 2500 is now over heating since I had the transmission replaced. I tow a 36' camper before I didn't have any problem now after 1hr of towing the light on the dash comes on and the temp looks like it about 220. Small bubbles come up when I look into the radiator. Before the transmission was replaced it never went above 200. I notice when I first start the truck and look in the radiator the fluid looks like it's about2/3rds full. The fluid looks red.

 

If you have bubbles in the coolant your head gasket is shot! Time to order some parts! Tranny has nothing to do with it!