Radiator Fan Clutch

My 2004 tundra overheats sometimes. How do I tell if the fan clutch is working properly or not?

 

With the engine off, how far does the fan spin when spun by hand?

 

It only turns a little more than 1/4 rotation....

 

Thats about how mine does. I dont think its in spec, but mine doesnt overheat.

ever cleaned the fins on your radiator? Like spray through with a waterhose?

frontward and backwards, make sure the fan shroud isnt full of leaves or whatever.

 

I was dealing with overheating occasionally at low RPMs and suspected the fan clutch was going out and not engaging properly, as the temperature would come down when I started moving. I had also read that the fan clutches have limited life.

At 165k I replaced it with OEM, along with my thermostat, water pump, radiator and t-belt. Since I did so much at once, I can't say for sure the fan clutch was the fix. Putting a rubber door stop between the crank and idler pulley helps for tightening/ loosening the 10mm bolts on the fan FYI.

My engine fan on the truck will do more than a 1/4 turn with the new fan clutch. Trying to turn the old clutch by hand (not on truck/ fan), there is a good amount of resistance.