2012 Silverado. 350,000 miles. Replaced original trans at 217K with OEM that had to be rebuilt at 107K. Heavy duty radiator installed 3 yrs ago.
Truck is a work truck, high mileage and pull a utility trailer daily on 200-300 mile roundtrip on mostly flat terrain. Trailer usually has Pioneer 1000 and Recon. Total weight of trailer and load is 3000#. Transmission will climb to 190-205 quickly, even if trailer is empty. No load temp is 175-180. Temps never got this high in the past. No CEL. Truck itself does not run hot, constant 210 or a tad lower. Tran mechanic and motor mechanic can't find any real issue. I may clean or even replace radiator again.
Any thoughts?
TIA