Pulled a 6% slope out of Laramie with 5000lbs on last week and the fan clutch wouldn't lockup. Is this a common failure with the Cummins engine and is it covered under the engine warranty? The temps went up to 230 then defueled. Could it be related in any way to the thermostat? DW

 

Twogun
Check that the cluch fan isnt too loose I had one go in a first gen and it took out the rad Not to sure about the warranty. Good luck