I pulled the trailer this weekend down to Sask Landing to the lake and it waas running warmer then normal, the tranny was running warmer then normal as well.
The Rads are fairly clean, what else coulld it be?200000km on the old girl

 

my buddy had this problem this past weekend.

noticed his radiator overflow hose had come disconnected from the over flow bottle. over time he had lost enough fluid for it start running hot. may wanna check fluid level.

 

Check your water pump weep hole, see if its leaking. Also how longs it been since you changed your coolant???

 

The rad is fairly clean itself. The hose is connected and working
The fluid has not been changed since i owned the truck (2Years)
The weep hole is dry and not weeping
Rad is topped up

Any other ideas?

 

Well possibly temp changes in ambient air. It is the middle of summer. How hot are you temps getting? I can see about 210* on the gauge, right past the mid mark when towing. When unloaded it stays at 200 til I get on it hard, then it will switch to 210 and back down.

 

220 and the tranny was running between 180 and 200