My fan wasn't spinning easily by hand, and when I revved it would spin very fast and loud. So I removed the clutch and let it soak in some varsol, after that it span very easily. I've read that you use Toyota silicone oil for it, but also read that in the service manual it calls for ATF. I'm guessing it doesn't matter, but i think silicone oil would be much thicker? The stuff that was in there seemed thicker than ATF. Anyways, I used ATF, put it back together but its leaking out when I drive. The o-ring was fine. The loud noise is gone which is awesome, and the car doesn't overheat (but its also cold up here) but I presume all the ATF is going to eventually leak out then the fan clutch won't work properly. There also seems to be some play in the fan, not sure if the bearing is bad and causing it to leak?

 

At this point I would just buy a good used clutch. They can be had pretty cheap and its not worth messing with an old one.