1942 - 1947 Chevrolet Shop Manual



	12-33

	HEADLAMPS The "Sealed Beam" headlighting system is used on all passenger cars and trucks. These lamps are designed so that the light source, the reflector, the lens and the gasket are all assembled in one securely sealed unit, known as the sealed beam unit. When the filament burns out or the lens becomes damaged or broken, the entire sealed beam unit is thrown away and a new one installed, thereby assuring maximum lighting efficiency throughout the entire life of the car. "Sealed Beam" headlamps provide two separate and distinct beams, giving the maximum amount of road illumination at all times. 1. A country (upper) beam (bright lights) is designed to illuminate the road evenly for considerable distance ahead of the car. This beam is for use on the open highway when no other vehicles are approaching. 2. A traffic (lower) beam is also provided and is low enough on the left side to avoid glare in the eyes of the oncoming drivers. It is intended for use on heavily traveled highways and should always be used well in advance of approaching vehicles. This beam is designed so that it does not throw any dazzling light into the eyes of the approaching driver under any condition of car loading. At the same time the distribution of light is such that the right side of the road is illuminated as far ahead as is practicable without causing glare on curves. The operation of the headlights is simple, allowing the motorist to use either the country (upper) or the traffic (lower) beam as traffic and road conditions demand by the use of the conveniently located dimmer switch on the left side of the toe-pan. When the country (upper) beams are lighted a red pilot bulb in the instrument cluster, at the top of the speedometer, will be illuminated, making it convenient for the driver to determine when the bright lights are on. Never pass an approaching car with this red light burning. ALWAYS SWITCH TO THE TRAFFIC (LOWER) BEAM WELL IN ADVANCE OF ONCOMING CARS. LAMP CONSTRUCTION The sealed beam unit (A) Fig. 69 is held to a sub-body (B) by a retainer ring (C) and three screws which may be loosened for removal of the unit. The sub-body forms a ball and socket joint with a lamp housing (D) and is held to the housing by four coil springs (E), plus the vertical adjustment screw (F), and the horizontal adjust-	ment screw (G). With this type of mounting the horizontal light beam adjustment can be made without disturbing the vertical light beam setting and vice versa. The sealed beam unit is provided with three locating lugs (H) which fit into corresponding slots in the sub-body. These lugs are so located that this unit can only be mounted in one position.

		Fig. 69-Sealed Beam Headlamp Parts With this system maintenance is greatly simplified, requiring only aiming of the beams and the replacement of burned out or broken sealed beam units. Neither dust nor moisture can get at the reflector because the entire unit is sealed. The units

		Fig. 70-Removing Headlamp Rim