TO: All ATP Technicians

FROM: James Strong, Customer/Technical Service Manager

RE: Ford 5R110W (Torqshift) In-Line Filter, ATP Part No. B-227

ATF, the bloodline of automatic transmissions. How do you keep the ATF clean and free flowing? Filtration of course!

During the life of the transmission, the main filter is designed to trap fine particles caused by normal "wear and tear". Eventually, the filter can become clogged reducing ATF flow and ultimately starve the pump for fluid.

On today's sophisticated vehicles, an in-line or cooler circuit filters are now being utilized as a secondary filtration system. So, what happens if this in-line or cooler circuit filter becomes clogged? You now run the risk of restricted ATF flow to the cooler and other lube circuits.

So, how can we accomplish the necessary filtration without causing damage to the transmission?

A parallel filtering system!

On 2003 and later, Ford E-F Series trucks equipped with the 5R110W (Torqshift) transmissions began using these parallel circuit filtration systems. (See Figure Below)

Reprinted with permission from the Nov/Dec, 2007 issue of GEARS magazine.

This setup is not as complex as it may seem. Notice that both cooler lines go into the filter's housing. The in-line filter acts as a barrier that separates the two lines.

The cooler creates a backpressure in the out going line and its pressure is higher than the return line. This variation of fluid pressure is what makes this system work.

The in-line filter's media is fine and has a capability of trapping small particles of 2 microns or larger. Even if the filter would become completely clogged, it will not affect the cooler flow because it is parallel to the system. This parallel circuit system provides extreme filtration without the danger of shutting down the cooler flow in the event of the filter becoming clogged.

Considering that the in-line filter is parallel to the cooler, it is the only thing that prevents the ATF from bypassing the cooler and simply returning to the transmission assembly. Strictly speaking, if you were to remove the filter from the housing, there would be nothing to force the ATF through the cooler. Granted, the filter is so restrictive, that this is what makes the system work.

The ATP Part No. B-227 in-line filter is constructed of this type of restricted media and is the OEM recommended replacement filter.

When servicing this type of transmission, these considerations should be followed:

• When flushing the cooler, disconnect the lines at the in-line filter and flush it from there to the cooler, or leave the filter in the housing, flush the system and then replace the filter element. If you flush the cooler (from the transmission lines) with the filter out of its housing, you will bypass the cooler during the flushing process.
• When replacing the filter element, be aware that not all filters are constructed the same. You will risk over-heating and premature transmission failure if you use a filter that allows the ATF to flow more freely then the restricted design filter. ATP has the correct O.E.M replacement filter.

Remember it is the filter's media that restricts the flow of the ATF and separates the two cooler lines which makes this parallel system work!

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