hey guys i recently had the same problem, i bought a water pump with clutch and started to take it apart, the shaft went from the impeller all the way through the clutch, i tried and tried and tried pulling it using several types of pullers and the aluminum clutch kept breaking, i said fuck it got out the die grinder and cut the hell out of it, now my water pump is clutch free!!!!! it was a little barbaric but hey it worked, i would have had to cut the shaft down anyways so i figured it would be just as easy to cut up the clutch, although i had a pile of shavings and a pile of chunks of clutch left when i was done!