If you work on cars that have fan clutches, you probably remove them like this:
However, its always a crap shoot whether the fan clutch is going to come off or if its partly seized. Turning an otherwise alright job (timing belt) into a a pain in the rear. For those who haven’t removed a fan clutch before: the problem is that the fan clutch spins when you try to undo the nut holding it on. That is why you traditionally need a hammer and a wrench, because you’re trying to shock the nut loose before the can clutch has a chance to spin. As you can imagine, if the nut is partly seized, it can become a nightmare.
If you do these with any frequency, I recommend getting the Lisle 43300 pneumatic fan clutch tool. The tool essentially connects the air hammer to the wrench. The air hammer can momentarily impact far greater than anything you would normally be able to do by hand with a wrench and a hammer.