Technical Changes

With the exception of United States government-mandated 5 mph bumpers in 1974 and ongoing mechanical changes, the Marathon remained virtually unchanged during its 21-year production run. However, Checker did comply with all safety and emissions requirements while in production. Notably, the Marathon's front suspension A-frames interchange with a 1956 Ford.

Some of these changes help in identifying the year of a Checker, and included:

• 1963: Front parking/directional lamps changed from white to amber
• 1964: Standard front lap belts
• 1965: Engines switched from Continental inline-6 to Chevrolet OHV-6 and small-block V8s
• 1966: Standard front and rear lap belts
• 1967: Interior safety package, including energy-absorbing steering column and wheel, padded dash, recessed knobs
• 1967: Dual-chamber brake master cylinder
• 1968: Side marker lamps on all fenders, amber in front, red in rear (round on all Checkers)
• 1968: Front shoulder belts for outboard passengers
• 1969: Headrests
• 1970: Locking steering column (Checker used full-size Chevrolet steering columns and wheels)
• 1974: Larger, heavier silver-painted "girder"-style bumpers
• 1975: Catalytic converter required unleaded fuel
• 1976: Radiator (AMC Matador), engine (Chevy 350 V8 2-barrel carb, cylinders were over-bored, requiring larger pistons and rings), transmission (TH 400: Turbo Hydra-Matic), differential (Spicer 44), front lower A-frame (Ford 56 Thunderbird), front upper A-frame (63 Lincoln Continental), steering was rear drag link until 1980, pittman arm bushing tends to loosen and should be tightened every 10k miles.
• 1978: Parallel action windshield wipers introduced
• 1978: New "Delta"-style Chevrolet steering wheel (sans the Chevy bowtie)

Engines

The engines used were originally Continental-built L-head inline-sixes (OHV units for the wagons), but these were exchanged for Chevrolet sixes and small-block V8s for the 1965 model year.^[4] These continued to change as Chevrolet introduced modifications, peaking with the 1969 L-48 350 V8 which produced 300 hp (224 kW) (gross).^[5] In 1969, a Perkins 4.236 L diesel non-turbo engine was available as an option for all models, but for only one year. By 1973, power for the 350 had decreased to 145 hp (108 kW) and in 1975 catalytic converters were introduced. For 1980, the engine lineup was changed entirely, with a 3.8-litre V6 replacing the old inline unit, and a smaller 267 ci (4.4 L) standard V8. The big news was the Oldsmobile LF9 engine, a 350 cu in (5.74 L) diesel V8.^[6]

End of Production

The final Marathon was manufactured in 1982, when Checker exited the automobile manufacturing business. The company continued operations for an additional 27 years producing body stampings for General Motors, Ford, and Chrysler, until January 2009, when it entered bankruptcy liquidation as a result of the downturn in the USA auto industry.^[7]

• 
  1971 Checker Marathon wagon
• 
  1972 Checker A12 Marathon sedan
• 
  1975 Checker A12 Marathon sedan
• 
  Checker Marathon badge

New York City

For decades, Checker was the taxicab of choice for New York City and many other American cities. The size of the car (seating many passengers), the robust construction, the lack of yearly changes to the styling (especially the 1958 and later models, simplifying parts management), and the bolt-on rear quarter panels all contributed to the Marathon's ubiquity on the streets of Manhattan.

The last New York City Checker cab retired in 1999, operated by Earl Johnson from 1978 onwards. The Marathon covered over 750,000 miles and had three engine replacements over the years.^[8]

Virtually any film set in New York City in the 1960s, 1970s, and 1980s will show a Checker Marathon. Many movies set in the 1950s and 1960s use Checker cabs built in the 1970s and early 1980s, since the bodies were virtually the same, and due to the lack of usable early specimens. Also, in works depicting the Soviet Union or East Bloc countries, such as the film Gorky Park ^{[citation needed]} and the original Mission: Impossible^[9] television series, Checker Marathons were used to depict Soviet-made GAZ-13 Chaika automobiles.

Kalamazoo

Apart from taxicab use, Marathons were also bought by police departments, most notably in Kalamazoo, where Checker had its factory.^[10]

The Vatican

In the late 1960s and into the early 1970s, some black SCV-plated (Stato Città del Vaticano - Vatican City) A12 Marathons were used to accommodate Pope Paul VI's entourage in motorcades.