Fierce Sparrow
Member
I've read a number of discussions on here regarding the various oil filters to use in the TO20, but upon close study of the placement of the suction tube of the oil pump, it appears to me that installing an oil filter on the center bottom cover retaining bolt is fruitless. The center retaining bolt is for just that, holding the bottom cover on. It is not hollow or have holes to allow oil to be drawn in to the oil pump. it is only a bolt with a female end to allow the retaining bolt for the bottom cover to thread into. The suction tube for the oil pump is off to the side of the center bolt. This means that when a smaller than original filter is slid onto the retaining bolt, no oil flow can go through the filter. The suction tube will draw unfiltered oil from the pan right past the filter. The only way this set up can work is if the filter was big enough to allow the suction tube to draw oil through the center of the filter. I see no other way for this to work.