Re: smoothcharlene: read this
You have to be careful about testing this way. Almost all viscous fan clutches are engaged when cold, since the fluid seeps back into the chamber after the engine has been off for awhile (hours). They need to be pumped out first. The best thing to do, is to start the truck, and run it for a minute or two (literally). This will ensure that the fluid chamber is emptied. Shut the vehicle off and try spinning the fan. If you have alot of resistance,the possibility of mechanical binding is there. On the other hand, if the clutch turns easily before the vehicle is started, you might have lost the viscous properties of the clutch fluid, and the clutch is therefore shot as well. If either of these scenarios happen, try testing the thing every morning for a few days, just to see if the problem is repeatable.