Kenworth T300 headlight bulbs utilize H4651 size for high beam and H4652 or H4656 sizes for low beam applications. The replacement chart covers 1995 to 1997 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Kenworth T300 uses sealed beam headlight units across its high beam and low beam positions for the 1995-1997 model years, meaning the entire lens-and-filament assembly is replaced as a single unit rather than swapping an internal bulb.
All three bulb types found in these specifications, the H4651, H4652, and H4656, conform to ANSI standards recognized in both the United States and Canada, and all operate at 12 volts.
Each of these sealed beam units follows the 4x6-inch rectangular form factor, a standardized housing shape that was widely adopted in North American commercial vehicle lighting.
The H4651 sealed beam unit serves the high beam position on the T300 across all three listed model years, 1995-1997, making it the consistent high beam fitment for this range.
The low beam position shows a fitment difference between model years: the 1997 T300 uses the H4652, while the 1995-1996 T300 uses the H4656, indicating these two units are not interchangeable across all years despite sharing the same physical housing size.
The H4652 is described as a variant of the H4651, and while both occupy the same 4x6-inch rectangular sealed beam format, they serve different beam functions and are not substitutes for one another in this application.
Because all units in these specifications are sealed beams, there is no separate bulb socket or replaceable internal lamp element involved in servicing the headlights on the T300 within this model year range.