Correct TO-20 Oil Filter

Apparently, a case can be made that the Agco oil filter is better for the TO-20 (and I assume all the early Continental engines) than WIX, FRAM or other brands. Do you know of a clear reason to think the AGCO filter is better? May 25, 2015.

The main reason I have recommended using the AGCO filter on TE and TO-20 tractors is it is one of the few filters I know of that is correctly designed to use with the TE/TO-20 which has oil flowing from the center of the filter to the outside. The flow of oil through this filter is opposite the flow of oil in other filters including those used on the TO-30, TO-35, F-40 and other Continental engines used on Ferguson tractors. Many manufacturers, including Fram, Purolator, AC, Wix, and Baldwin list an oil filter for the TE/TO-20 tractors but, now either show no listing or list the same filter as used for the TO-30, TO-35, etc. The TO-30 and TO-35 filter, though they have the same dimensions, are not supposed to be used on the TE/TO-20.

The Ferguson Shop Manual contains the following admonition: “CAUTION: Do not interchange the two filter elements. The filter element for the TO-30 engine, Part No. TO-18662-A, is designed for oil flow from the outside to the center. The filter element for the TO-20 and TE-20 engines, Part No. TO-18662-2, is designed for the oil flow from the center to the outside. If the elements are interchanged in the engines, the relative flow of oil will be reversed and plugging will result.”

Many suppliers today list the same oil filter for a TE/TO-20 as for a TO-30, TO-35 or F-40. Sadly, unless there has been a major change in the design of oil filters to allow them to flow oil from either the inside out or the outside in, those oil filters can damage a TE/TO-20 engine. The design of the bypass valve in an oil filter would seem to make flowing oil in either direction impossible.

As indicated above, the TO-30 oil filter will fit the TE/TO-20 but it is not to be used in the TE/TO-20. Several years ago I did an article for Furrows on this topic. I believe the title was, “Which Filter is Right for Your Ferguson Tractor?” A couple of years ago when I noticed some oil filter charts/lists recommending the same filter for the TE/TO-20 as for the TO-30, TO-35 and F-40, I contacted one of the manufacturers, Wix I believe. After playing phone tag I was finally able to talk to someone supposedly in the know. The person I spoke with said he’d never heard about a TE/TO-20 using a filter in which oil flowed in the opposite direction from other oil filters and pretty much blew me off. Therefore, in the interest of preserving TE/TO-20 engines, I began recommending using only AGCO oil filters.

If a manufacturer lists a different filter number for a TE/TO-20 than they do for a TO-30, TO-35 and F-40, they probably still offer the correct filter for a TE/TO-20. If a manufacturer lists the same oil filter for TE/TO-20 engines as for a TO-30, TO-35 and F-40, I would not use it in a TE/TO-20.