Okay...when you look at a dart (maybe other sequnce pumps...unsure) you see a shaft with a rubber washer on a shaft between the pump housing? and the motor(think thats right...where the water comes in and goes out

and the motor) there is quite a bit of saltcreep...is this normal? the shaft "seems" to be turning okay...sounds louder than it did but its not running any hotter than it was... should i be worried...should i look at something? I emailed manufacturer but no reply.
Thanks guys/gals