Carl mine looks very similar its a laser tool. But the pins are too short. I experimented outside the engine with the sprocket that was supplied with the new pump and its as u say - just rotate the tool and the pins more or less fall into place with the sprocket and neither the sprocket or tool can rotate. But when i try to do the same thing in the water pump service opening the tool just spins and spins wont lock into place.............in the words of clarkson "how hard can it be" from this i can only assume the pins must be too short....
Here is a pic of the set up outside the engine as u can see the locking pins dont extend much beyond the sprocket actually just flush with it really....
