[Mrmerlin]

To fix the fan clutch you need to remove it then carefully cut the silicone sealant thats under the Bi metallic strip, slide this to one side then it will release.
Once this is done then you will see a brass pin in the center of the fan clutch , it is held in place with a green rubber seal,remove this pin and with a magnifying glass check it for scratches if its scratched you may be able to polish it with some fine grit sandpaper hold the pin in a small piece of rubber tubing so it wont be damaged .
Then you will also need to get some new silicone fluid.
Try the Local Toyota dealer they sell a tube of silicone its about 2 oz.
Toyota Part number is 08816-03001.
Depending on how much freewheeling the fan does you may need 2 bottles of it, I used one bottle to refill my fan.
If the pin is damaged then you will have to get another one or just buy a new fan clutch. The pin is not available so you may have to find a used fan to get this part from or make one