The Kenworth L700 headlight bulb specifications include H4651 and H5001 sizes for high beam applications and H4652, H4656, and H5006 sizes for low beam applications. The replacement chart covers 1981 to 1987 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Kenworth L700 uses sealed beam headlight units across all listed model years (1981-1987), meaning the entire lens-reflector-filament assembly is replaced as one unit rather than swapping an internal bulb.
All sealed beam types specified for the L700 operate on 12V and conform to ANSI standards recognized in both the United States and Canada.
The H4651 and H4652 are both 4x6-inch rectangular sealed beam units, with the H4652 classified as a variant of the H4651. Despite their close relationship, they serve distinct functions: the H4651 is the high beam unit and the H4652 is the low beam unit for 1986-1987 model years.
The H5001 is a 4-inch square sealed beam unit used as the high beam on the L700 for model years 1981-1983, while the H5006 is a 5.75-inch round sealed beam unit serving as the low beam for those same years. The two units are not interchangeable due to their differing form factors.
For the 1984-1985 model years, the low beam transitions to the H4656, a 4x6-inch rectangular sealed beam unit, while the high beam continues to use the H4651. The H4656 and H4651 share the same physical format but are not listed as variants of each other and are not interchangeable between beam positions.
A notable shift in headlight format occurs between the 1983 and 1984 model years on the Kenworth L700, where both the high beam and low beam move from round and square sealed beam units to 4x6-inch rectangular sealed beam units.
Because each sealed beam type has a specific ANSI designation tied to its size, shape, and beam pattern, substituting one type for another, such as using an H4651 in place of an H4652, would not produce the correct beam output for that position.