Ford’s Cruise-O-Matic and the C Family of Automatic Transmissions (Part IV)

Last on our coverage of the discontinued story of Ford’s historic Cruise-O-Matic automatic transmission, we spent time in Russia. Communist automaker GAZ liked Ford’s automatic and decided to rework it slightly into its “own” transmission rather than pay Ford to build it under license. The GAZ two- and three-speed automatic transmissions remained in use in the company’s passenger cars until late in the 80 yearswhich was a very long time for a late 50s transmission to live.

Shortly after GAZ made its copies, the real versions of the FX/MX Cruise-O-Matic and Ford-O-Matic were nearing the end of their respective lifespans. The two-speed was naturally the first to go.

By the turn of the ’60s, the writing was already on the wall for the two-speed automatic. Three speeds were the way of the future! The first of the Big Three to drop the two-speed was Chrysler, which discontinued its Powerflite in 1961. This final year it was only available on lower level Dodge and Plymouth models.

And while Ford followed suit soon after, General Motors wasn’t so ready to give up a two-speed. Their Powerglide lasted until 1973 and was offered in the Chevy Nova and Vega. In the end, Powerglide was only available to bargain skaters who selected the Turbo-Thrift 250 inline-six. Back to Ford.

The simple Ford-O-Matic as you please continued as an offering in low-end Ford and Mercury models through the 1963 model year. Recall our previous entry that Ford marketed the transmission three-speed (although it used first gear in a few Drive situations) until the arrival of the Cruise-O-Matic. This transmission was a true three-speed, so the Ford-O-Matic changed to a two-speed transmission to help with marketing differentiation.

Ford needed a more modern automatic that was cheaper to manufacture, lighter, and could be used in more applications than the old two-speed. In the early sixties, the replacement transmission was already in development and would eventually be called the C4.

The old Ford-O-Matic was a very heavy transmission because it was made of cast iron. Ford used a slightly lighter material when designing the replacement for the FO-M: aluminum alloy! The C4 had a three piece case design which consisted of the main case, bell case and tail case attached. In addition to lighter materials, it used a simpler Simpson planetary gear design. Recall that the original Ford-O-Matic and its derivatives used a Ravigneaux epicyclic gear train.

Created by American engineer Howard Simpson (1892-1963), the Simpson gear train uses two planetary gears with a common sun gear. With its design, a Simpson gear allows three or four forward gears, neutral and one reverse gear. The design remained in use into the 2000s, when it was superseded by more complex transmission designs with a greater number of gears. The main advantage of the Simpson design was its simplicity, which meant it was lightweight. Weight reduction was the main development goal of the C4.

The C4 used a different shift pattern than the Ford-O-Matic, and even other automatic passenger cars in general. At first, its shift pattern was Park, Reverse, Neutral, Drive 2, Drive 1, and Low. Drive 2 and Drive 1 have been abbreviated as D2 and D1 on gear shift indicators.

D1 meant the transmission started in first gear, then shifted to second and third as usual. Using D2 meant that the transmission started in second gear and first was not used under any circumstances. D2 and D1 were unfamiliar drive modes to consumers, and Ford later conceded and changed the layout to the much more familiar P, R, N, D, 2, L. When cars with the C4 were marketed, Ford called the “SelectShift” feature of the two different Drive modes.

The C4 was used in medium-duty vehicles, usually with a straight-six or V8 engine with a displacement of 302 cubic inches (5.0 liters) or less. When it debuted in 1964, the C4 was immediately used in Lincolns, where it would remain until 1981. Other early uses included Ford’s Mustang, Ranchero, Mercury Comet, and Econoline minivans. .

Later in the decade and into the 70s, it extended to the Mercury Montego and the Capri, as well as the Ford Torino, Thunderbird, Maverick and Bronco. In addition to its continued Lincoln use, the later 70s saw C4 appear in the Ford Fairmont, Granada, LTD and the Mercury Bobcat, Monarch and Zephyr.

The C4 was sometimes used with a 351 Cleveland V8, particularly the M-code version. This use required a larger bell housing and was only available from 1970 to 1971 in cars like the Ford Torino and Mustang, and the Mercury Cougar.

C4s are generally grouped into those made from 1964 to 1969 and examples produced between 1970 and 1981. Earlier examples used a 24-spline input shaft, which was upgraded for 1970 to 26 spline. The clutch hub was also updated in 1970 and had its own 26 splines. The 26-spline clutch hub was very short-lived: it was overhauled the following year; downgraded to 24 splines.

Ford’s first alloy three-speed turned out to be a simple and reliable automatic, which was fortunate given the gearbox’s wide spread within the Ford family. However, the C4 with its mid-weight limitations would not be enough for buyers of the big V8 engines offered by Ford throughout the 60s. So the heavier FX version of the Cruise-O-Matic was replaced by a newcomer for 1966: the C6, or SelectShift Cruise-O-Matic in marketing terminology.

Much like the C4, the C6 focused on simplicity, lower construction costs and reduced weight. Also, the old MX in particular was notorious for sapping an engine’s power, in a bad case of parasitic power loss. The bigger V8s of the ’60s produced big torque figures while gulping fuel, and the C6 was designed to handle more torque than the MX.

Designed in the same basic way as the C4, the C6 used the same setup with a Simpson planetary gearset. It differed from the C4 in that it was the first automatic designed to run with a Borg-Warner flexible shift band. The bands replaced the clutch plates and were intended to allow longer life and make the transmission more durable. Clutch plates were still used on the lower and reverse gears of the C6. The transmission’s plates and valves were made of tough composite materials, which meant the gearbox could handle up to 475 lb-ft of torque.

Unlike the C4, which only used two different bells (normal and 351M), the C6 had five different bells. They were designed to fit Ford’s various major V8 engine families, as well as the 300 straight-six. The six alongside the Windsor V8 and 351 Cleveland V8 all used a Windsor bell-housing design. The more powerful M-code 351 Cleveland, 400 V8s and 385 (Lima) family which included 370, 429, 460 and 514 cubic inch displacements used the 460 bell.

There was also an FE bell crankcase, for the Ford-Edsel line of V8s in production between 1958 and 1976. Displacements for the FE engine series ranged from 332 to 428 cubic inches and spanned two different engine generations. Two other bell housing designs were less common: one for diesel engines and a special Lincoln design used only from 1966 to 1969.

The Lincoln bell housing was only used on MEL (Mercury-Edsel-Lincoln) V8 vehicles. The MEL was an engine built in Lima, Ohio, which was superseded by the aforementioned 385 engine family. The bell housing was only used on Lincolns for three model years that had the 460 or 462 cubic inch engines. The bell housing was specially shaped on the passenger side to make room for the air conditioning housing used by Lincoln.

Early heavy-duty C6 uses included the Mercury Meteor, Cougar, and Comet, as well as larger-engined Lincolns, as mentioned above. Ford immediately used it in the LTD, Thunderbird, Fairlane and Galaxy. The C6 didn’t see as many mainstream models as the C4, but progressed through the 70s into the Bronco, LTD II and the ugly Mustang Cobra II. The C6 also managed a long lifespan, but lived much longer than the C4. It was used throughout 1991 in the Bronco and until 1996 in the standard F-series pickups. The F-250 and F-350 heavy trucks used it until 1997.

In our next entry, we’ll end the 60s with one last take on the original Cruise-O-Matic. It was a kind of Frankenstein designed to combine the best features of Borg-Warner’s original automatic design.

[Images: Ford]

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