I have a 36" Kohler 16 HP snapper WB about 3 years old. I recently noticed after mowing that what looked like oil had leaked onto the deck under the transmission. Not sure but i think its coming from the knob on the side that spins when the mower is in drive. I don't know the technical term for this...the instructions i have are for a hydro and my mower is belt driven. I am wondering if this is something i can fix on my own or if i should take it in to Stovall?