The Ford L-Series trucks are a range of heavy-duty trucks that were built by Ford between 1970 and 1998. The first dedicated Class 8 truck produced by the company, the L-Series range replaced the N-Series short conventional (derived from the F-Series). The Louisville Line encompassed a wide range of models through the Class 7-8 GVWR ratings and for medium-duty, severe-service, and vocational applications; many were produced as semitractors. The line would become one of the most popular series of trucks Ford ever produced.
The L-Series was produced in the Kentucky Truck Plant near Louisville, Kentucky, which eventually gave rise to the nickname "Ford Louisville Line" trucks.
In 1976, the LL/LTL-9000 was introduced. Designed as a truck for long-haul drivers, the LTL-9000 was a competitor to the Kenworth W900, Mack Super-Liner, and Peterbilt 359. Fitted with a set-forward front axle and a longer hood, this version had more room for larger powertrains. In 1978, Ford gave the LL/LTL-9000 its own grille and headlight styling, including one of the first uses of the Ford Blue Oval in North America. Although the L-Series would see few revisions throughout its production, elements of its design would see use in other Ford vehicles. In 1974, the W-Series cabover received a larger grille similar to the chrome version on the L-Series. For 1978, the F-Series/Bronco grille was given a similar eggcrate grille pattern. In the 1980 redesign of the medium-duty F-Series, the hexagonal shape of the grille was carried over; it is a theme used in all Super Duty trucks since their 1999 introduction.
In 1984, the rest of the L-Series became one of the last North American Fords to adopt the Ford Blue Oval; as with the LTL-9000, it was placed above the grille. In 1988, the L-Series changed its grille design from an eggcrate design to that of horizontal chrome bars; the Ford Blue Oval became centered. In addition, rectangular headlights became standard in 1991. 1992 saw the introduction of the set-back front axle version of the LL/LTL-9000, designated the LLS and LTLS-9000.