Its standard for this transmission to sound like its filled with loose parts when operating around the dock. My previous 1986 Power Slot and this 2004 196 sound the same.
I have read that's why Master Craft switched to 15W-40 Motor oil for this transmission around 2004. But the rattle is still there.
Before the engine/transmission warm up, there is no rattle with the thicker cooler oil.
Has anyone used a heavier weight oil in this Transmission ?
I wouldn't mess around with a lube that isn't recommended by the factory, unless people experienced with the boat have done it successfully. I know this is a long shot, but just asking.