Sta-Rite Dura-Glas 1HP replacement

I have a Sta-Rite Dura-Glas 1HP 220V which was installed with our new 96,000 litre pool 3 years ago. The pump ran about 10 hrs/day from May to September each year.

I have a STA-RITE Cristal-Flo Filter Sand Filter Model T-249BP-1. The system ran at about 10psi, and I backwashed around 15. We live in Ontario Canada, I disconnect it each fall and store it in the basement until spring. When connected, the pump is unsheltered.

Today, I decided to start preparing for pool season and pulled the pump out of storage. I took the clamp ring off to ensure the throat is clear, put some o-ring lubricant and put it back together. I primed it and plugged it in but it howled. Took it apart to make sure I reassemlbed it properly. I left it on (howling) long enough to draw water out of the pool with filter set to backwash so it didn't see any pressure. When I pulled the motor off, it or howls when plugged in by itself. I suspect its the bearings.

I read Spurgeon's thread dated April 12, 2008. I too think I should be getting a lot longer than 3 yrs out of a pump. Same problem, same pump model. The only thing I can think of is that I am using a SWG and I have often let water spray directly onto the pad when backwashing. Could the exposure to salt water contribute to corrosoion?

Can these motors be serviced?
If so, should I to to a motor repair shop, or pool maintenance store?
If it can be serviced, should I replace the entire pump or just the motor?
If I replace just the motor, should I replace the seal too?

I appreciate any help you could provide.
Thanks