Kenworth T450 high beam headlight bulbs use H4651 size while low beam headlight bulbs use H4656 or H4652 size specifications. The replacement chart covers 1993 to 1997 vehicle production 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 T450 uses sealed beam headlight units across all listed model years, meaning the lens, reflector, and filament are fused into a single assembly. When the filament fails, the entire unit is replaced rather than an internal bulb.
The H4651 and H4656 are both ANSI-standardized 4x6-inch rectangular sealed beam units operating at 12V. The H4652 is a variant of the H4651, sharing the same form factor and voltage rating under the same ANSI framework applicable in both the United States and Canada.
The high beam position on the Kenworth T450 uses the H4651 sealed beam unit consistently across the 1993-1997 model years.
The low beam position shows a fitment difference: the 1993-1996 model years use the H4652, while the 1997 model year uses the H4656 instead.
Because the H4652 is a variant of the H4651, the two share a close relationship in design, though they are not listed as interchangeable. The H4656 is a distinct unit from both, and substituting one sealed beam type for another without confirming the correct designation risks a mismatch in beam pattern or filament configuration.