Ford Mustang/Cougar 1964-1973 Repair Guide



See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: An identification tag located on the driver's door jam contains the transmission code

Three different automatic transmissions have been used; the C4, C6, and FMX.

The C4 is a light-duty, dual-range, three-speed unit with an aluminum case. It is used in all six-cylinder models, all V8s prior to 1967, and all V8s of less than 351 cu in. since 1967, with the exception of small block high-performance engines.

The FMX, a dual-range three-speed unit with an aluminum case, is used with all 351 V8 engines from 1969 to the present, except for the 1971 351 CJ and Boss 351, and the 1972 351 HO.

The C6 is a heavy-duty, dual-range, three-speed transmission in an aluminum case. Its applications include all V8 engines larger than 351 cu in., all GTs, and all high-performance V8 engines-regardless of size-from 1967 to the present.