D2 Cat adjustable fan belt pulley

I agree that taking a punch to the threaded hole for the locking bolt will wreck the threads for the locking bolt.Where are the 2 clamping bolts you mention? Are they bolts holding the fan to the water pump?This is a running motor with all in place such as radiator,fan,existing fan belt,etc.Do you need to get the hood off to gain some access? This is a 5j7822 by the way.

If you only have the single locking bolt on the fan side the spanner will not work. The two lock tab version is the one that will accommodate the pin spanner.

Mine is the single locking bolt type.Any other ideas?

let it soak in PB blaster over nite then take a brass rod or punch and work it back and forth to loosen the pulley half. Some times a large pipe wrench may be needed if the other does not work. A little elbow grease goes a long way.

I have used a strap wrench after letting soak. Doesn't always work, but better then braking the pulley right off the bat. Tim

I have used a strap wrench after letting soak. Doesn't always work, but better then braking the pulley right off the bat. Tim

I've been successful placing the tip of a flat blade screwdriver in the notch of the adjusting ring, and the handle on a protrusion on the block, then grab the fan and turn..... one side of the block to loosen, the other side to tighten.

I use a similar technique, just usually not a screwdriver, but anything that you can jam between one of the webs on the rear of the pulley and something else that will not move. You want to make sure whatever you use gets a good rest on the pulley so you don't chip it or have the bar or whatever get too crosswise and push the pulley forward instead of around if that makes sense.

I have also used a bit of heat with a torch on one that wouldn't break free and I didn't have time to soak. Your bearings are regreasable and unless you go crazy with the torch, you can usually get it to loosen right up long before it gets too hot for the seals and bearings. The belt is against the hot part, so you might want to keep it dampened with water while heating if you have to get it real hot.