The fourth generation Ford F-Series was a line of pickup trucks and commercial trucks produced from 1961 to 1966 by Ford Motor Company. Sleeker and wider than its predecessor, the new F-Series introduced several firsts to the truck line. In Canada, the F-Series continued to be distributed by Mercury dealers as the M-Series.
Due to poor market reception, and rumors that overloading caused the doors to jam shut, the unibody trucks were dropped midway through 1963. The result was that some 1963 trucks use the bed from the 1960 and '61 style. The 1963-64 models differ in appearance from the later models of the fourth generation in that the turn signals are in the grill, and in the 65-66 models the turn signals are above the headlights. Also, from 64 onward, the flare over the rear wheel arch was extended out to the taillights, rather than flowing over the wheel opening.
While the body remained largely unchanged, the 1965 F-Series was given an all-new chassis. This would go on to underpin the F-Series until 1979; consequently, many parts from 1965–1979 interchange such as brakes and motor mounts. An all-new Twin I-Beam front suspension was introduced with coil springs; 1965-1966 F-Series trucks are distinguished a "TWIN I-BEAM" emblem on the front fender. Twin I-Beam front suspension would go on to be adopted across the light-duty Ford truck lineup and is still in use in the 2013 E-Series vans. To give the 1965 F-Series the same passenger capacity as the majority of its car lineup, the F-Series now included a 4-door crew-cab model.
In 1965, the 300-cubic inch (4.9 L)straight six was introduced (a larger version of the 240-cubic inch Six). It had 7 main bearings and timing gears (no chain or belt). The 300 six would remain in the F-Series lineup until the end of the 1996 model year. With the introduction of the 208-hp FE V8, output surpassed 200 hp in the F-Series for the first time
F-100 (F10, F11, F14): 1/2 ton (4,000–5,000 GVWR max)
F-100 (F18, F19)(4×4): 1/2 ton (4,000–5,600 GVWR max)
F-250 (F25): 3/4 ton (7,400 GVWR max)
F-250 (F26)(4×4): 3/4 ton (4,900 GVWR max)
F-350 (F35): 1 ton (9,800 GVWR max)
The Camper Special was built heavier for the slide in campers that were becoming increasingly popular during this time. Ford still offered a "Low GVWR" version of each model. In 1965, the Ranger name first appeared as a styling package for the F-Series pickup trucks. The interior featured bucket seats (from the Mustang) and a curtain over the gas tank which was behind the seats in the cab.