Oh. I actually have big enough hands that I just got a good grip on the pulley and gave it a good cinch.

I did have to do it twice though. The first time, I thought (as has been mentioned here) that the reverse threads would be enough to hold it on without much pressure, but the first time I started it up the fan flung right off. Damn lucky I didn't damage the radiator.

Definitely want some amount of torque to home it in place. Either use a strap wrench or find some other way to hold it in place and tighten it down.

 

thanks, I might pick up that tool.....


and thanks for all the replies!!