Starting with the 1976 model year, Ford F-250 4x4 trucks were built with an open knuckle, disc brake, Dana 44 monobeam axles which replaced the drum brake, closed knuckle design Dana 44 which had been used since 1959. Initially, Ford retained the remote mount transfer case, high-boy chassis but with a Dana 44 open knuckle front axles instead of a closed knuckle axle used through 1975. The 1976-1977-1/2 axles can be identified by the type of wheel hub used. These 1976-1977-1/2 axles have disc brakes and a wheel hub that is drilled and tapped on its outboard face in order to bolt on either a solid drive flange (full time) or external mount plastic dial Spicer hub lock (part time). 1977.5-1979 F-250 trucks are low riders with direct mount transfer cases. All 1977.5-1979 Dana 44 axles used an internal spline type wheel hub. Heavy-duty trucks could be ordered with an available 4500-pound capacity Dana 60 front axle for 1978 and 1979. 1979 was the last year Ford used a beam type Dana 44 front axle in the F-250 series. From 1980 through 1997, all 4x4 F-250 trucks used an Independent Front Suspension (IFS) drive axle.
