Wistlo is speaking of the mechanical seal aka shaft seal and Impeller which are relatively easy and cheap if you're a diy guy. I'm not sure what would go bad with the Impeller but if he said it went bad I guess he saw it.
Sorry for the delay, just saw this.
As I recall (it's been awhile, 2013), the impeller was deformed, slightly warped by overheating. One don't want any deformations in spinning components as that will wreak havoc on bearings and seals (and make noise, too), and if the impeller disintegrates the failure could be catastrophic (destroying the housing, locking up the motor, etc.).
These were the two parts I replaced:
Hayward SPX3010C 1-Horsepower Impeller Replacement for Hayward Super Ii Pump
Amazon.com: Hayward SPX3005R Impeller Ring Replacement for Hayward Super Ii Pump: Garden & Outdoor
www.amazon.com
Hayward SPX3005R Impeller Ring Replacement for Hayward Super Ii Pump
Amazon.com: Hayward SPX3010C 1-Horsepower Impeller Replacement for Hayward Super Ii Pump: Garden & Outdoor
www.amazon.com
Everything else on the pump is original (except the basket, that cracked and needed replacement at some point.) And the motor, too; those have lasted 2-5 years. Pump was there when I bought the property in 1997.
Somewhat off-topic: I'm currently debating whether to upgrade to a variable-speed pump, but I'm worried about durability especially for such a costly piece of hardware. My HVAC system had variable speed high efficiency motors when originally installed (2002). We get a lot of lightning here and those motors failed during storms more than once, and ultimately the manufacturer discontinued them. I now have one system with the variable speed motor and the other with the standard one-speed motor. I also had to replace a dishwasher control board that I suspect succumbed to a lightning-induced power surge. I wonder how an electronic variable speed pool pump motors stand up to our spectacular lightning.