I am due for 100,000 mile maintenance and I recently had to replace my thermostat. I decided to replace my thermostat ahead of my maintenance so I could play with my GKs during their Christmas break. Since I stripped off my hoses and such to get at the t-stat I thought I would go ahead and pull the fan, then just run without it until I did my maintenance. I plan to replace it with a fixed fan since I tow about 1/2 the time (bass boat).
I used the hammer and wrench technique on three different occasions with no positive results. After studying the fan pulley I tried some screw drivers and other pries to try and lock the pulley while I wrenched it off, also to no avail. This work did spark and idea to make a tool that would lock the pulley against the engine lift bracket mounted at the front of my engine. If I could make one it should REALLY simplify this process.
I found a piece of steel rod that is an orphaned under car spare tire handle extension. It is 5/16 to 3/8 in diameter. Using a grinder I shaped a tip that would easily go into the holes on the fan pulley. Using a vice I put a 90 degree bend about 7 inches from the tip (looks like 8 inches would work even better), then using a hack saw I cut the end off so the bend had about a one inch tail.
Using a vice and hammer I put a bend in the rod so it would lay flat against the bracket when it was in the pulley hole.
Using the tool I locked the bracket in place by turning the pulley with a wrench then with just a bit of pressure broke the fan nut free. Now with the tool I can break my fan loose in 1 - 2 minutes. Time to make the tool was about 30 minutes, with an extra minute needed to break the fan nut loose.


For those of us that have a grinder, vice, hack saw and a piece of steel rod laying around, this could be a great way to go if the hammer-the-wrench technique does not work.
I am so impressed with the ease of pulling my fan, and the room in the bay that I am not going to replace my water pump and maybe not my idler/tension bearings when I do my 100,000 maintenance, just replace my timing belt. Looks like a gamble of an extra hour to hour and a half in time, if I ever need to go in again. AT 200,000 I'll do those deeds then.