Exactly how easy should motor shaft/impeller spin?

CajunGuy

Well-known member
Apr 6, 2016
304
Louisiana
#1
Just finished rebuilding my Whisperflo pump with a new seal plate (grommet housings were cracked bad causing shift, impeller was rubbing against diffuser face), new shaft seal, and new gaskets/o-rings.

Got everything put back together and just screwed the impeller on, but it seems like it turns/spins with the same amount of force as it did prior to me rebuilding the pump. My question is...are you suppose to be able to spin it and it spins freely in multiple circles on its own for a while? Or is it suppose to be able to just manually turn by hand? I can turn it by hand with no problem, but if I tried spinning it like a wheel/top, it will not spin freely for any period of time.
 

CJadamec

TFP Expert
Apr 29, 2016
2,194
Quaker Hill, CT
#2
It shouldn't spin like a top but you should be able to rotate it 360 degrees smoothly with out it having any binding or sticky spots. It's hard to describe the amount of force it should take to spin it but it shouldn't be much. There will be drag on the shaft from the seal, motor bearings, and mass of the motor rotor which probably has some residual magnetism.
 

CajunGuy

Well-known member
Apr 6, 2016
304
Louisiana
#3
It shouldn't spin like a top but you should be able to rotate it 360 degrees smoothly with out it having any binding or sticky spots. It's hard to describe the amount of force it should take to spin it but it shouldn't be much. There will be drag on the shaft from the seal, motor bearings, and mass of the motor rotor which probably has some residual magnetism.
OK it sounds like I'm alright then. It was previously rubbing against the diffuser face and getting stuck, but now (after rebuild) I can turn it all the way around in a circle without any spots where it gets hung up or hard to turn. I noticed once I put the impeller on there was a little more tension, I'm assuming this is normal from the seals pushing together which apply a little more pressure to turn the shaft?
 

CajunGuy

Well-known member
Apr 6, 2016
304
Louisiana
#4
So the impeller/shaft should get a little more tension to turn it once the impeller is installed because of the pressure of the spring loaded side of the seal now pressing against the impeller side of the seal right? I can still rotate the impeller/shaft in a full circle with no problem, just got slightly more tension in it once I put the impeller on.