Truck temp varies widely under normal driving, loaded or unloaded. Believe the problem is the fan clutch. Considering replacing the fan with either a flex fan or an electric fan... both of which involve removal of the fan clutch and therefore a possible solution to the problem.

Head gasket is OK... cooling system is fine, so can't really come up for any other reason for the temp flux except for the fan clutch. 93,000 miles on truck.

Will the electric fan be adequate for cooling the truck (pulling a 6700 pound gooseneck) or is the flex fan the only real way to go?

Thanks,
-Mike

 

A clutchless fan will always out-cool an electric fan. The question is does the mechanical fan rob more power than it's benefits are worth to the cooling system. In your case, absolutely not. Most definately install a wide blade flex fan, without a clutch. Make sure the fan sits so that the blades are halfway into the shroud. If that doesn't suffice, you can always add a small pusher fan to the front of the radiator, but I doubt that will be necessary. If you have an automatic transmission, and do not have an external cooler for it, this would be an excellent time to install one. I'm sure you are aware of how hard towing can be on an auto tranny, and the temps that will be created. A cooler is a little insurance.

Take care,
-Chris