OK; Now I'm curious. On the 1500 the filler plug is located on the right side of the final drive, to the rear of the axle and below the center line of the axle or looking at it from the end of the axle, I'd say the plug is about 8:00 o'clock or so.
The manual says to fill it to the bottom edge of the fill hole. I can't see if you use this hole how you could over fill it. When the oil reaches the bottom edge it starts to run out. You'd have to be like greased lightning to over fill it enough and get the plug back into over fill it.
So the question for future reference is; where on the 1200 is the fill plug.
Just curious. Haven't changed final drive oil on a 1200 yet, and want to get it right if I ever do.
From the Northwest Corner
Ron