Hi. My first post on this forum. I inherited from my father-in-law an older Simplicity Sovereign 18 hp lawn tractor. I want to change the oil and I've found the drain plug ... but there is no opening in the motor mount plate to let the oil through into a catch-pan. It appears that the oil is supposed to drain onto the motor mount plate and just run where the heck it wants to. The Kohler service manual indicates the drain plug, but the diagram doesn't show the motor while its ON the mounting plate. Is this what is supposed to happen, or am I missing something?