Article 1270 - Dislodged Transmission Filter Assembly, FMX Automatic Transmission Models PHA, B, C

TSB #85 - February 9, 1968
(1968 Ford with 302 CID Engine Built Prior to February 1, 1968)

When customers complain of slipping or dragged-out shifts, or "abnormal noise", the transmission filter position should be checked to make sure it is correctly installed on the regulator.

A number of instances have been found in which the dacron filter assembly has been dislodged from the pump inlet port of the subject models. In some cases, the filter is moved over far enough that the inlet port of the regulator is completely covered by the dacron material; in other cases, there is a partial overlap between the regulator port and the opening in the grommet. Either condition can cause pump cavitation, resulting in the conditions described above.

In some cases, it may be found, when the pan is removed, that one end of the large retaining clip is disengaged, which could permit the filter to become dislodged. However, it is possible for the filter to be incorrectly aligned or completely dislodged even though both ends of the retaining clip are still fastened in place. Therefore, the position of the filter must be checked by actual examination. In addition, it is possible for the same symptoms to be caused by regulator to case retaining bolts. The regulator bolt torque should be checked while the transmission is partly disassembled.

If, after disassembly, there is any question as to whether the filter was correctly installed, check the upper surface of the filter; a circular witness mark or depression corresponding to the outline of the regulator port may be found on the surface of the dacron or overlapping the rubber grommet.

If the filter is found to be dislodged, it should be carefully repositioned and the clip and pan installed. The transmission should then be retested prior to any further servicing. If the symptoms have disappeared, it can be assumed that the displaced filter was the cause of the problem. If the symptoms persist, other service procedures must be applied, as outlined in the appropriate shop manual.

Transmissions on vehicles built after February 1, 1968 have a metal mesh screen and clip instead of dacron.