New and improved all-glass sealed beam headlamps have recently been introduced and they are a new concept in headlamp engineering. With increased wattage these new lamps provide better visibility for night driving, with either upper or lower beams, especially in bad weather. The new headlamps provide greater seeing distance as the passing beam projects up to 80 feet farther ahead, a little more effectively and minimizes annoying stray light or glare toward an approaching vehicle. The new lamp is fully interchangeable with the old type; in fact one of each could be used on a car and it would have a good lighting system. However, to obtain the maximum benefits from the new type lamp, both sides of the car should be equipped with the new type unit.

The Parts Department advises that the new lamps are available for use in those states in which approval has been obtained. (Refer to Dealer Parts & Accessories Bulletin No.3, dated January 31, 1955, for a list of states that have approved the use of the new lamps.)

These new lamps are available under Gr. 2.727, Part No. 456795 (6 volt for 1940 through 1952 and 1953-40); identified by No. 5040 stamped on back of reflector. Gr. 2.727, Part No. 456796 (12 volt for 1953-50, 70 Series and 1954-1955); identified by No 0 5400 stamped on back of reflector.

The present sealed beam unit, Group 2.727, Part Nos. 193142, 193195 (6 volt) and 454642, 454643 (12 volt) will still be carried by the Parts Department for service replacements.

The improved sealed beam lamp can be further identified by noting the metal shield over the filament which can be seen through the lens. See Figure 58.

1955 Buick Sealed Beam Headlamps

1955 Buick Sealed Beam Headlamps

We would like to stress the importance of correctly aimed headlamps not only so the owner receives full benefit from the improved lighting, but because the range and power of this new head lamp will make even slight variations from recommended aiming specification hazardous to an approaching motorist, due to glare.



Headlamp aiming should be checked (corrected if necessary) whenever a sealed beam unit is removed, regardless of the reason for removal.

The procedure for aiming the new sealed beam headlamps is exactly the same as has been used for past sealed beam units except that the center of the brightest area is aimed two inches below the headlamp center instead of three inches as formerly specified.

Headlamp aiming has always been a difficult procedure in service because of the lack of a perfectly level floor area. The following procedure may be used with a slightly sloping floor providing the surface on which the car rests is not uneven.

Select a permanent location for aiming headlamps which has a comparatively even, flat surface for the car to rest upon and where the car can be parked with the headlamp lens 25 feet from a vertical wall or aiming screen. The aiming screen has movable lines making it ideal for this usage. The surface of the wall or screen must have a white non-glossy finish such as obtained with whitewash or equivalent. It must also be in a darkened area. Tires must be properly inflated and the car unloaded when the aiming is done.

NOTE: If a regular constructed headlamp aiming screen with movable lines is not available a simple setup can be made as follows. On the wall or flat surface selected for aiming, install two six foot runners in a vertical position, eight feet apart, and parallel to each other. Over the top of the two vertical runners, install an eight foot runner in a horizontal level position. On the top runner install three vertical lines on movable hooks with weights on the bottom end to hold the lines tight. On the two side runners install two horizontal lines on movable hooks with a small coil spring, such as a screen door spring, at one hook to hold these lines tight. The runners can be made from 3/4″ round pipe, small channel iron or strips of wood nailed or bolted in place. The hooks or strips of wood nailed or bolted in place. The hooks can be made from small gauge strap iron and bent to fit on to the runners. The lines should be at least 1/4in diameter and dark in color such as sash cord. All the line hooks must be free to move the entire length of the runners for adjustment (See Figure 59).

1955 Buick Headlamp Aiming Hooks

1955 Buick Headlamp Aiming Hooks


First, paint a line on the floor parallel with the wall and 25 feet from it. Place the car so that the faces of the headlamp lens are directly above the line. Move the front end of the car up and down several times to make certain that the car is in a normal free position.


  1. On one side of the car place yardsticks upright directly opposite the center of each wheel. Tape each yardstick in position making certain that neither the tires or yardsticks rest in holes or pockets in the floor. (See Figure 60).
1955 Buick Headlamp Aiming Height

1955 Buick Headlamp Aiming Height

  • Stand behind the car and sight over the top of the two yardsticks and have a helper mark this point on the wall or screen. Repeat this same process on the other side of the car and then place the horizontal line through these points to establish the Reference Line as shown in Figure 60 and Figure 61.
  • 1955 Buick Headlamp Aiming

    1955 Buick Headlamp Aiming

    NOTE: If the floor slopes slightly sideways the reference line will slope correspondingly thus cancelling this objection when the final aiming center have been located on the wall.

    1. Stand directly behind the car and sight through the center of the rear window, through the windshield, and over the center of the radiator ornament to locate the car centerline on the reference line. Place a vertical line at this point at right angles to the reference line. (See Figure 61).
    2. Take the distance between the top of the yardstick and center of headlamp lens and add 2″ for loading allowance. Place a parallel line equal to this total distance below the reference line. This line is the aiming line for up and down adjustment of the headlamp beam. (See Figure 62).
    1955 Buick Headlamp Aiming Arrangement

    1955 Buick Headlamp Aiming Arrangement

    Example: Distance from top of yardstick to center of Headlamp lens: 6″; add 2″ loading allowance 2”

    Therefore, in this example the aiming line would be placed 8” below the reference line

    Measure the distance between the centers of the two headlamps. Place a vertical line half this distance on each side of the centerline.

    1. This establishes the aiming points “R” (Right) and “L” (Left). (See Figure 62).
    2. Remove the headlamp doors to make the adjusting screws accessible. Facing the lamp the screw for adjusting the beam up and down (vertical) is at the top, and the screw for sidewise (horizontal) adjustment is at the left. (See Figure 63)
    1955 Buick Headlamp Screws

    1955 Buick Headlamp Screws

  • Turn on the upper beams and cover left hand headlamp so that the light will not show.
  • Adjust the two aiming screws on the uncovered right hand lamp so that the center of the brightest spot of the light strikes the aiming point “R” on the right side of screen.
  • Cover the right hand lamp and adjust the left hand lamp in the same manner so that the center of the brightest spot strikes aiming point “L” on the left side of screen.
  • The above procedure may also be followed in adjusting the older type sealed beam headlamps except that three inches should be added instead of two inches as shown in Figure 62 and example.



    It has been brought to our attention that some service personnel are increasing the initial spark plug gap on 12 volt systems to improve idling.

    On a 12 volt system there isn’t sufficient voltage available to fire a spark plug after the gap has been increased to .045 to .050″. Since the gap will automatically increase with mileage, at the rate of .001″ per 1000 miles, it can readily be seen that with an initial setting of .040″- .045″ the car would operate for only a few thousand miles before it would be necessary to have the plugs removed and reapped.

    Since we desire to have plugs operate at least 12 to 15 thousand miles before re-gapping, we do not concur with the idea of having a larger initial gap setting; therefore, for good spark plug life the production setting of the spark plug gaps should be adhered to.



    VOLTAGE REGULATOR TESTING Model1118825 Regulators (1954 & 1955 All Models)

    Field reports indicate that there may still be some misunderstanding concerning testing and adjustment of the above regulators. It is imperative that these regulators be checked with a battery in the circuit. This applies to bench test as well as test on the vehicle. Due to the design of this regulator there is no accelerator winding on the voltage coil and as a result the armature vibration is slower than earlier types. Therefore, due to voltage fluctuations, the settings can be checked accurately only if the charging circuit is stabilized with the battery. Delco Remy and the 1954 Shop Manual both specify that these checks be made with a 1/4 ohm fixed resistor of not less than 25 watt capacity connected in series.



    In order to conduct a field test, a certain percentage of new generators having an armature part number 1933855 wound with nylon insulated wires in place of cotton insulation, will go into production in the near future on Flint built cars only.

    These generators can be identified by the letter “N” stamped on the frame adjacent to the name plate. The armature, as usual, can be identified by the part number 1933855 stamped on its laminations.

    If a nylon insulated armature should fail in service, armature part number 1923535, now stocked by the Parts Department, may be used as a replacement. All defective nylon-type insulated armatures should be properly tagged and returned to the attention of V.O. Wirt, through your local zone, in a shipment separate from other warranty material with a letter stating how and when parts were shipped.

    The Return Parts Tag should be properly filled out, including model, serial number, mileage, delivery date and any information that is available, relative to armature failure with any additional comments deemed necessary. It will not be necessary to submit special reports unless circumstances warrant them.




    There have been reports of short circuits in the directional signals. Most of these short circuits are caused by one of the control lever housing support bolts contacting and chaffing the directional signal wiring. See view 8 Figure 64.

    1955 Buick Signal Switch Housing

    1955 Buick Signal Switch Housing

    This condition can be corrected with the signal switch housing removed as follows:

    1. Remove screw which holds wire retainer to signal switch housing, then carefully position wires and bind with adhesive tape as shown in view A. Figure 64.
    2. Replace wires, retainer and attaching screw, being certain to make wires conform to housing contours, then reinstall housing.



    1955 Models

    We have received a few reports of run-down batteries and burnt generator armatures on 1955 air conditioned equipped cars. Whenever a complaint of this type is reported, the generator and generator regulator should be checked as follows:

    • Re-charge battery
    • Check generator output as outlined in Section 10-23, Paragraph 8 of the 1955 Shop Manual.
    • Check operating voltage of voltage regulator as outlined in Section 10-26, Paragraph C and D in the 1955 Shop Manual. If the operating voltage is below 14.5 volts, reset to 14.5-15.0 volts. The limits given in the 1955 Shop Manual are 14.0-15.0 volts.
      CAUTION: Never set regulator higher than 15.0 volts. If voltage regulator is set higher than 15.0 volts when hot, premature distributor point failure and bulb life will occur when operating at colder temperatures.
    • Check the operating current of the current regulator as outlined in Section 10-26, Paragraph C and D in the 1955 Shop Manual. If the operating current is below 30-amperes, reset to 30-33 amperes. The limits specified in the 1955 Shop Manual are 27 -3’3 amperes.
      CAUTION: Never set current regulator higher than 33 amperes. If current regulator is set higher than 33-amperes premature failure of the generator armature insulation will occur. Armature failure may not result until after the car has been operated two or three months depending upon driving conditions.

    NOTE: The electrical load of the air conditioning equipment on 1955 Buick cars, plus ignition load, is approximately 17 -amperes when the car is operated at speeds between 25 and 35 MPH.



    1955 Models

    Reports have been received that the clip holding the wiring harness to the bracket on left front fender skirt has in some cases cut into the insulation. See Figure 65.

    1955 Buick Wiring Harness

    1955 Buick Wiring Harness

    To correct this condition, a change was made in production approximately August 1 whereby a new type clip Group No. 2.559 Part No. 1338561 was installed. See Figure 66.

    1955 Buick Wiring Harness Friction Tape

    1955 Buick Wiring Harness Friction Tape

    As a precautionary measure, it is suggested that the wiring harness be checked on all cars in for other service, and if the new type clip is not present as shown in Figure 66, wrap two thicknesses of friction tape around the harness at this point; then reinstall harness in clip. If harness is found to be damaged, it should first be repaired before the tape application is made.

    Service mechanics are urged to use care when removing or replacing wiring harness from all clips so that the insulation is not damaged.



    1955 Model

    Following is a reprint of Special (Red Band) Service Letter Dealer No. 154 dated March 24, 1955.

    Several reports have been received regarding generator pulley failure whereby the outer half of the pulley breaks away from the inner half. (See Fig 67).

    1955 Buick Generator Pulley

    1955 Buick Generator Pulley

    In order to eliminate this condition, changes have been made in pulley design to increase the brazed (welded) area where the two pulley halves are joined together and a wider flange has been incorporated on the front half of the pulley. These changes not only increase the strength of the weld but also prevent deflection of the pulley during operation. Examples of the old and new type pulleys are shown in Figure 68.

    Whenever a defective generator pulley is replaced, the new type pulley (Fig.68) should always be used. The group and part numbers will remain the same; therefore, the pulley will have to be identified by visual inspection.

    Note: This is not a campaign item and replacement is necessary only when generator pulleys are found defective.

    In the event the dealers’ parts stock contains the old type pulleys, these may be returned to the Parts Warehouse along with Form WH-7 and the latest type pulley ordered for replacement purposes. New type pulleys are available through local Parts Warehouse.

    In the event an engine vibration complaint is encountered, it is suggested that the generator pulley be inspected for cracks in the area shown in Fig.67, as this could be the cause of trouble. If cracks appear, it will be necessary to replace the pulley.



    1955 MODELS

    Most of the complaints of horn ring dead spots are caused by the horn ring spring. First job; were equipped with a clockwise wound spring that would tend to uncoil and swell in diameter as the nut was screwed down into the housing. This action would force one of the center coils of the spring into the gap between the contact plate and spacer, preventing the horn ring and contact plate from being depressed far enough to make contact and blow the horn. See exploded view Figure 69.

    1955 Buick Horn Ring Assembly

    1955 Buick Horn Ring Assembly

    The correction for this situation is the installation of the new counter clockwise wound spring bearing the same part number as the original. For proper adjustment, the adjusting nut must be turned down until it bottoms, then back off 1/2 turn.

    CAUTION: Do not drive the nut down hard as damage to parts may result.