Ford C4 Transmission

Ford C4 Transmission

The Ford C4 is a three-speed, medium-duty automatic transmission introduced on 1964 model year vehicles and produced through 1981. The C4 was designed to be a lighter and more simple replacement for the original Ford-O-Matic two speed transmission being used in smaller, less powerful cars.

Because of its cast iron construction, the Ford-O-Matic was very heavy. In designing the C4, Ford used an aluminum alloy, three-piece case (bell housing, main case, and tailhousing). The aluminum case and the use of a more simple Simpson planetary gearset reduced the weight significantly. It was primarily used with Ford's inline six-cylinder engines and small V8 engines (see Ford Windsor engines), usually up to 302 in³ (5.0 L). By comparison, the 351 Windsor and 351 Cleveland small and intermediate-block engines were backed by the medium-duty FMX or the heavy-duty C6 that debuted in 1966. Some C4s were built with a larger spread bell housing to use with 351M V8s, but these are rare.

The early model C4 (1964–1969) used a .788-inch 24-spline input shaft, which was upgraded in 1970 to 26-spline and .839-inch. The upgrade also included a matching clutch hub of 26-spline. In 1971, Ford went to a 26/24-spline input shaft, meaning the torque-converter side is 26-spline and the clutch hub is 24-spline.

The C4 was also found with valve bodies requiring a different number of bolts, 8-bolt vs 9-bolt. A 9-bolt valvebody can be used on either case, but a nut & bolt must be used on the valve body in the empty hole, dropping the bolt in from the top and using the nut on the bottom/filter side.

Modified C4s remain popular with hot rodders and drag racers due to their simplicity and durability.

Year & Model breakdown:

• 1964–1966 Select Shift, 24/24 spline, castings: C4, C5, C6
• 1967–1969 Select Shift, 24/24 spline, castings: C7, C8, C9
• 1970–1970 Select Shift, 26/26 spline, castings: D0
• 1971–1979 Select Shift, 26/24 spline, castings: D1, D2, D3, D4, D5, D6, D7, D8, D9

Applications:

• 1973–1977 Ford Bronco
• 1974–1982 Ford Cortina
• 1965–1983 Ford F-Series
• 1964–1970 Ford Fairlane
• 1978–1983 Ford Fairmont
• 1965–1970 Ford Falcon
• 1975–1982 Ford Granada
• 1975–1980 Ford LTD
• 1970–1977 Ford Maverick
• 1965–1981 Ford Mustang
• 1965–1979 Ford Ranchero
• 1968–1981 Ford Thunderbird
• 1968–1976 Ford Torino
• 1964–1981 Lincolns
• 1977–1980 Lincoln Versailles
• 1974–1980 Mercury Bobcat
• 1972–1981 Mercury Capri
• 1964–1977 Mercury Comet
• 1967–1981 Mercury Cougar
• 1975–1980 Mercury Monarch
• 1968–1976 Mercury Montego
• 1978–1981 Mercury Zephyr