Why GM shelved the Chevrolet Cadet after the war

The Chevrolet Cadet was a General Motors experiment that ran from 1945 to 1948, an attempt to build a light, cheap four-seat car designed from the start for mass production. It never reached a showroom. It is remembered today for its suspension, which carries the name of the engineer who led the project.

Why did General Motors want a cheap light car?

Many economists in 1945 expected a slump like the one that followed World War I, when the first peak of the car industry crisis had come in 1921. Some General Motors leaders wanted a light car that could be sold for no more than $1,000 in mass production, a goal that needed radical changes to the design and production technology. Reaching that price meant changing both the existing design and the production methods, not simply trimming a known model.

The brief set the bar high. Kerb weight was to be around 2,000 to 2,200 pounds (roughly 900 to 1,000 kg), the cabin had to seat four, and the main dimensions were to match the 1935 Chevrolet while the outside stayed as compact as possible. Earle Steele MacPherson, a GM engineer, was placed in charge of the Chevrolet Light Car Project in spring 1945.

His team included engine specialist Earle W. Rohrbacher and Ralph Johnson, his former colleague from the Hupmobile company, who worked on the gearbox and rear axle. Tom Scott handled the transmission units and Theodore Dowerty was a test engineer. The car took the name Chevrolet Cadet soon after the project began.

A light, cheap four-seater that never reached production, and whose engineer gave his name to the strut suspension.

Why did MacPherson keep the classic layout?

MacPherson tested a production Chevrolet with different loads and found that a rear-engined car could not offer enough stability and handling. Front-wheel drive needed costly constant-velocity joints, which cut across the budget, so he kept the engine at the front and drove the rear wheels.

Rear engines were widely tipped as the future in those years, but for this car the verdict went the other way. Front-wheel drive was also judged a poor fit for traction and handling.

The classic layout had its own problem in a small car. The hump over the transmission tunnel cut into cabin space. MacPherson moved the compact three-speed gearbox back under the bench-style front seat and joined it to the clutch housing with a hollow tube, which removed most of the tunnel. A second hollow tube linked the gearbox to the final drive housing and gave the cabin still more room.

Because the transmission units were fixed rigidly to the body, the drive passed through shafts without universal joints, which saved a good deal of money. Four wheels of 12-inch size, small even by the standards of the time, sat at the body corners. The compact package still gave a wheelbase of just over 2.7 m (106 in) and a roomy cabin.

What made the 2.2-litre engine unusual?

The 2.2-litre (134 cu in) six was conventional in layout but full of ideas that were ahead of their time. It had overhead valves and made 65 PS (48 kW; 64 hp), and two small flywheels, one at each end of the crankshaft, let it sit at a steep rearward angle without losing ground clearance.

That tilt lowered the transmission shaft, which opened up the cabin. The clutch used a diaphragm spring with hydraulic operation, years before such features became common on production cars. Packaging the engine this way was not a styling exercise: the lower shaft line was the reason the cabin could be roomier. For economy the final drive used bevel gears rather than hypoid gears, and the outer joints on the half-shafts were bell-shaped, like the inner joints on the Zaporozhets, which removed the need for a separate splined joint.

What was the MacPherson strut suspension?

It combined the shock absorber and the spring into a single spring-damper strut. That strut also guided the wheel and, at the front, acted as the steering pivot. Arms and reaction rods took the longitudinal and lateral loads, giving the layout that later carried MacPherson's name.

The upper mounts of the guide struts sat on a tubular cross member of the front subframe and on strengthened wheel arches at the rear. The suspension was independent at both ends, and its simple construction made it cheap to produce and easy to fit to the car.

How well did the prototypes perform?

By mid-1946 four prototypes had been built, and they showed quite good performance. Tom Scott, a member of the team, later said the car's handling earned a better verdict than the Cadillac of that era.

Styling and body

The body looked very modern for its time. It had pontoon-style sides with almost no wheel-arch cut-outs, a curved windscreen and rear window, and a wrap-around bumper, which was very fashionable then. Production cars with this look only became common in the first half of the fifties, so the Cadet was ahead of the market in its styling as well as its mechanics.

Why did the Cadet never reach production?

Four prototypes were built by mid-1946, and a plant had been constructed in Cleveland, Ohio, with production planned from late 1947. Series production never began. Forecasts, costs and shortages of materials all weighed against the car, and an official order from GM president Charles Erwin Wilson halted the work on 13 September 1946.

The market did not behave as the forecasters expected. Buyers were eager for any new car the makers could produce, and most firms had little need to restyle their prewar models. Sales specialists at Chevrolet said they could not sell the 300 thousand cars a year that the project needed to pay back.

The costs were a second problem. The sums showed that the target price could not be met, because the design was simply too original and advanced. Postwar shortages of pig iron, steel, copper and lead made any expansion of GM's programme hard to justify.

Development did not stop at once. The team was cut to a fifth of its size, and in summer 1947 a fifth prototype appeared with a simplified dependent rear suspension on single-leaf springs. A similar rear arrangement was used in the early 1960s on the Chevrolet Chevy II, another compact Chevrolet. Work went on until September 1948, by which time MacPherson had already left Chevrolet for Ford.

Where did the suspension go after the Cadet?

The Cadet had no direct successor within GM. MacPherson's strut spread from the Ford Vedette, built by Ford's French subsidiary, and became widely used across the industry. General Motors only adopted the layout on its production cars in the mid-1970s, copying European designs.

Some Cadet ideas were reused elsewhere. A similar gearbox arrangement, with the transmission pushed further back and combined with the final drive, appeared on the Le Sabre concept car and on the first-generation Pontiac Tempest. GM sent the last surviving prototype for scrap in 1968.

Did the Cadet name survive?

The name came back in the early 1980s as the cheapest trim level of the Chevrolet Cavalier, which was sold as the Chevrolet Cavalier Cadet. The car itself never reached production, so that trim badge was the name's return to the GM range rather than a sequel.

Chevrolet Cadet specifications