[tkeracer619]

Use a thick synthetic grease for the gearsets.

Chema, the pump with 45,000 hours that is brushless is silent. Pure silent. That is why in the very first post I recommend them specifically. People buy all sorts of pumps based on their budget. If you purchase a pump with brushes know there is going to be noise. Brushes squeak, these are not fan motors. The pump that makes all sorts of noise is old. I doubt there are many people out there who have electronics in service at that age on a saltwater aquarium. In the end it still functions and I could rebuild it if I wanted but the rebuild would cost more then I have in it ($150 5 years ago). Heck the head alone goes used for $100 these days and that is still in like new condition...