Water pump sprocket
 

I have a 06 maxima 3.5 that i pulled the timing cover off of and noticed that only the water pump has significant wear on the sprocket teeth. Like major wear. But all the other sprockets are smooth and factory-like condition. I have a new genuine replacement but i dont want it to get eaten up like the one thats on there. Any suggestions?

how many kms on the motor?
otherwise check for bearing wear on all components on the belt (will prob need to remove belt) and see if it is just the water pump clapping out- in which case good. replace it.
if its something else too then replace that bearing/component.

Well....yeah, of course replacing everything should fix the problem, but WHY is only the water pump sprocket showing significant wear from the backside of the chain turning the pump sprocket while all the other sprockets are still in factory-like condition?
https://cimg8.ibsrv.net/gimg/maxima....4f984249ba.jpg
https://cimg7.ibsrv.net/gimg/maxima....daa234961b.jpg
https://cimg6.ibsrv.net/gimg/maxima....f19a001ada.jpg
https://cimg0.ibsrv.net/gimg/maxima....a9d69f4050.jpg