Noises are very rare and usually caused by the friction of two parts rubbing against each other. Applying a small amount of lubricant (3-in-1 oil, WD-40, or silicone) to the areas in photo (attached) should fix the issue. It is not necessary to disassemble your seat. Be careful not to overspray the rest of the seat or lid, and wipe off any excess. After applying the lubricant, re-attach seat and open/close the seat and lid a few times to spread the lubricant.
If the tips above do not work, please Contact Us and send us a note.