Never had it happen to me but it seems possible that if the pump to pan clearance only allowed for say, a 5 gallon per min. inlet flow & the pump put out 10 GPM @ the RPM you're at then you gonna have a problem soon. Only way to know for sure is check & be sure there'a lots of opening there. I'd weld a nut on the bottom & use a slide hammer puller & make some more room. Doug