Mack WL Headlight Bulb Size

The Mack WL headlight bulb size specifications include high beam options of H6024, H4651, and H5001, along with low beam alternatives of H6024, H4652, and H5006 for this truck model. A replacement chart documents bulb specifications across the 1982 to 1983 production range.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

High Beam Headlight

Years	Bulb Size
1982-1983	H6024 (With 2 Round Headlamps)
	H4651 (With 4 Rectangular Headlamps)
	H5001 (With 4 Round Headlamps)

Low Beam Headlight

Years	Bulb Size
1983	H6024 (With 2 Round Headlamps)
	H4652 (With 4 Rectangular Headlamps)
	H5006 (With 4 Round Headlamps)
1982	H6024 (With 2 Round Headlamps)
	H4656 (With 4 Rectangular Headlamps)
	H5006 (With 4 Round Headlamps)

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6024
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651
ANSI standard (US & Canada). 4-inch square sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5001
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652
ANSI standard (US & Canada). 5.75-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5006
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656

Other Locations

Additional Notes

The Mack WL for 1982-1983 supported three distinct headlamp configurations: a two-round-lamp setup, a four-rectangular-lamp setup, and a four-round-lamp setup, each requiring different bulb sizes across both high and low beam positions.
All bulb types specified for the Mack WL are sealed beam units conforming to ANSI standards recognized in both the United States and Canada. In a sealed beam design, the lens, reflector, and filament are fused into a single unit, meaning the entire assembly is replaced rather than an individual bulb.
The H6024 is a 7-inch round sealed beam unit operating at 12V. It serves as both the high beam and low beam in the two-round-lamp configuration, meaning a single part number covers both functions in that setup.
The four-rectangular-lamp configuration uses 4x6-inch sealed beam units across all positions, though the specific part number varies by year and beam function. H4651 covers high beam for 1982-1983, H4652 covers low beam for 1983, and H4656 covers low beam for 1982, making direct interchangeability between these part numbers inadvisable without confirming the beam function.
The H5001 is a 4-inch square sealed beam unit at 12V, designated for the high beam position in the four-round-lamp configuration for 1982-1983.
The H5006 is a 5.75-inch round sealed beam unit at 12V, used in the low beam position of the four-round-lamp configuration for 1982-1983. Its physical format differs from the H5001 despite both belonging to the same headlamp system.
Within the four-rectangular-lamp configuration, the low beam part number changed between 1982 and 1983, shifting from H4656 to H4652. Both are 4x6-inch rectangular sealed beam units at 12V, but they carry distinct ANSI designations and are not listed as interchangeable in these specifications.
The H4652 is described as a variant of the H4651, both being 4x6-inch rectangular sealed beam units at 12V. Despite their physical similarity, they are assigned to different beam functions and should not be treated as substitutes for one another.