Boost pump making god aweful sound

[dissfigured]

Rebuilt my boost pump because the ceramic seal had cracked and it was leaking.
I got the new impeller, and seals.

I had removed that tiny little rubber gasket that goes around the axel for lack of a better term.
At the shop I said, I need that little one for the rod that turns the impeller.

Guy at the shop said you don't need that it really doesn't do anything

1. Is that true?
2. Could not having that be why my boost pump is making a horrible loud high pitched whining noise?

Kinda sounds like metal on metal.
It is so loud I really can't use the pump because it will irritate neighbors.

 

[mas985]

Your boosters bearings are probably shot because the seal leaked water on to them.

 

[OldPoolMan]

Ditto. Bad bearings due to the leaking seal. The rubber piece you mention is called a slinger. Its meant to keep water out of the front of the motor, like from a leaking seal