Kenworth T600A headlight bulbs utilize H4651 for high beam and H4656 or H4652 for low beam applications, with each bulb size corresponding to specific lighting functions. The replacement chart covers vehicle production years spanning 1986 to 1997, detailing bulb size specifications across the model's manufacturing period.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Kenworth T600A uses the H4651 sealed beam unit for the high beam headlight position across all listed model years from 1986-1997, making it the most consistent bulb specification in the dataset.
The H4651, H4656, and H4652 are all ANSI-standardized 4x6-inch rectangular sealed beam units operating at 12V. Because the light source is fused within the lens and reflector assembly, the entire unit requires replacement rather than an internal bulb swap.
The H4652 is a variant of the H4651 within the same 4x6-inch rectangular sealed beam family. Despite their physical similarities, the two types serve distinct low beam applications and are not interchangeable with each other or with the H4656 without confirming the correct designation for a given year.
The low beam position on the Kenworth T600A does not follow a single consistent specification across all listed years. The 1987, 1989-1990, and 1994 model years use the H4652, while 1986, 1988, 1991-1993, and 1995-1997 use the H4656, making year verification necessary before sourcing a replacement unit.