Peterbilt 357 Headlight Bulb Size

Additional Notes

• The Peterbilt 357 (1986-2008) uses four distinct headlamp system configurations across its model range: a 2-rectangular-lamp setup, a halogen capsule setup, a 4-rectangular-lamp setup, and, for 1986-1997 models, a 4-round-lamp setup. Each configuration requires entirely different bulb types, and no single bulb type is interchangeable across configurations.
• The H6054 is a 5x7-inch rectangular sealed beam unit operating at 12V. It functions as both the high beam and low beam in the 2-rectangular-lamp configuration, meaning the same unit serves both lighting functions rather than separate dedicated bulbs for each beam mode.
• The 9004 is the only non-sealed-beam type in these specifications. It is a dual-filament halogen bulb with a P29t base, rated at 12V and 65W/45W, where the higher wattage filament serves the high beam and the lower wattage filament serves the low beam. It is used across the full 1986-2008 span in halogen capsule headlamp configurations.
• The H4651 and H4652 are both 4x6-inch rectangular sealed beam units operating at 12V, with H4652 classified as a variant of H4651. Despite their close relationship, the specifications assign H4651 exclusively to the high beam position and H4652 exclusively to the low beam position within the 4-rectangular-lamp configuration, making them non-interchangeable by position.
• The H4656 is also a 4x6-inch rectangular sealed beam unit at 12V and appears in the low beam position of the 4-rectangular-lamp configuration for certain model years, alongside H4656 appearing in place of H4652 in that same position depending on the year. This means the low beam requirement within the 4-rectangular-lamp setup is not uniform across all years.
• The H5001 and H5006 are sealed beam units used exclusively in the 4-round-lamp configuration present on 1986-1997 models. H5001 is a 4-inch square sealed beam unit assigned to the high beam, while H5006 is a 5.75-inch round sealed beam unit assigned to the low beam. These two units differ in both physical form and function within the same headlamp assembly.
• All seven bulb types in these specifications conform to ANSI standards applicable in both the United States and Canada, and all operate at 12V. Six of the seven are sealed beam units, meaning the lens, reflector, and filament form a single non-serviceable assembly that is replaced as a complete unit rather than by filament alone.
• The 4-round-lamp configuration, which requires H5001 for high beam and H5006 for low beam, is present only in the 1986-1997 portion of the specifications. From 1998 onward, the specifications list only three configurations, with the round-lamp option no longer included.