for the grinding noise, check the bearings for corrosion and check the gear teeth for the slightest amount of wear. know also that stainless steel newell gears are notoriously noisy, even when brand new.

I had the pleasure and honor to meet Carl once, some years back. Talking wahoo with Carl was awesome, no, it was better than that!
He believed the grinding of his straight cut gears actually acted as an attractant for wahoo. That was and still is, good enough for me.