Water pump grenaded today--

[projectile]

Doug- I had the same problem a few years back. My problem started when I installed a "Heavy duty/towing" fan clutch. It took too long to disengage and would overspeed the fan. The fan vibration would rock the flange back and forth until it moved on the shaft. Luckily the belt was thrown before the fan fell off the pump shaft. I went back to the standard clutch instead of the heavy duty one and it solved my problem. I thought heavy duty meant that it could withstand more rpms. It is really designed to just move more air. May not solve your problem, but thought I would share...