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1934-39 Chevy Tail Light Loom

Wednesday, October 26th, 2016

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GM always made sure the taillight wires were protected from unexpected damage! Because vinyl covered wires were not yet invented, the cloth covered wires required extra protection. This is certainly true for wires in the wheel well area that are continually hit by road debris.

This was done by a 5/16 diameter inch galvanized metal flexible conduit. The length was different between the ½ ton and 1 ½ ton which depended on the distance from the back of the taillight to the factory hole in the frame rail. See Photo. All made in the USA.

Good News: This kit is available especially made with flexible conduit crimped on brass ferrules on ends and the curved metal connector that secures it to the oval taillight. This connector must be used to correctly attach the wires to the original oval taillight.

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Different length on 1 1/2 ton.

Early Chevrolet 1930’s Taillights – Car or Truck?

Wednesday, August 17th, 2016

The 1931-1932 Chevrolet cars were equipped with chrome plated oval taillights. Their attractive design added to the overall appearance of the new passenger car. This was to help attract potential customers that were experiencing some of the worst years of the Great Depression.

Surprise!

We find that GM reused parts of these car lights again on the 1934-1939 Chevrolet Trucks. This was the housing or bucket and the many internal connection parts to secure the light bulbs. This saved GM much rather than designing new tooling.

As repeats they were not noticeable to most because the buckets were now painted black and only the painted outer ring and lens were different.
Just another way GM saved much tooling money by passing on earlier car parts to their trucks a few years later. After all: Trucks were for work. Their appearance was secondary.

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1931-32 Car Taillight

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1934-39 Truck Taillight

1937-38-39 Headlights – Car Verses Truck

Monday, August 15th, 2016

With the headlight ring and reflectors now being reproduced for the 1937-1939 Chevrolet truck, we are occasionally asked, “Will these parts also fit that year of Chevy passenger car?”

Sorry they will not on US made trucks! The passenger cars have a slightly smaller lens and reflector. The car reflector has a diameter of 7 inches while the same year of truck is 7 5/8 inches.

To give the car headlight a more streamlined appearance the bucket (without the ring) is 11 ½ inches long. The trucks have a length of 8 inches.

Just a note: We discover that these three years of trucks in New Zealand and Australia were given car headlights! (In those years their trucks were imported from Canada). No doubt this extra length on these trucks requires extra care in raising the hood. Otherwise the back of the headlight bucket will receive continual scrapes on the paint due to the extra length.

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1937-39 Passenger Car Headlight Bucket. Plus Chevy trucks in New Zealand and Australia

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1937-39 Truck Headlight, US Production

Early Headlight Bulbs

Monday, August 15th, 2016

Almost all of the headlights during at least the mid to late 1930’s had double filament bulbs. They were 32cp (candle power) on either the low or high beam setting. This made replacing the burned out bulb a “no brainer”. You just pushed the bulb in the receiving socket and gave it a slight turn. This locked the bulb in place.

Even if you were 180 degrees different each time the bulb was added, it made no difference. Both high and low beam filament in bulb was 32cp.

NOW ENTERS A NEW VARIABLE. An aftermarket company later introduces a new bulb with a brighter high beam! It is rated 32cp low and 50cp high. Better roads allowing faster driving needed a brighter high beam.

Because the original bulb receiving sockets remain the same, this new 32cp / 50cp bulb must be placed in the socket just right! In other words, the high beam 50cp contact of this modern light bulb must contact the high beam wire in the harness. The bulb being added can only fit one of two ways. If incorrect you will have the 50cp as the low beam. Not good!

To prevent this low-high beam problem from occurring on the assembly line or at least at the dealership, a different bulb base was introduced. In 1937 on new vehicles and continued until the sealed beam began in 1940. The different holes in the flat ring around the bulb base prevented a mistake. The bulb could only be attached in one way. Most all vehicles by then were 32cp/50cp.

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1934-36 Duel Filament Bulb

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1937-39 Duel Filament Bulb

The Earliest Sealed Beam Bulbs

Two major changes have occurred in General Motors sealed beam bulbs. The early version are actually not sealed beams as we buy them today. They were first installed on vehicle assembly lines in 1940. The perfectionist restoring his truck to exact original specifications must have the correct headlights for his year. In very competitive judging, it’s these details that can make a difference. No doubt, replacement bulbs from a small GM dealership could sometimes be placed on newer vehicles a few years after the units were discontinued, however this article is based on bulbs you would have bought new from the factory during that particular year.

From 1940 through about 1955 seal beams had a double filament small bulb built inside. The large glass reflector in the back was sealed from the elements. It stayed bright even after the inside bulb burned out. It was not like earlier open reflectors that could tarnish with age due to the silver plating. The assembly comes with a metal black back attached for support. If the outer glass gets a rock hole, the light continues to work well. The filament is still encased in the smaller argon gas filled glass bulb through in the photo it is hidden behind the large glass cover.

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1940 through about 1955 (above)

More Modern Seal Beam Bulb

The first truly sealed beam bulbs, as are in auto part stores today, were introduced about 1955. Between the reflector and the outer glass covering is the open unprotected filament (no small internal bulb). The total interior is filled with argon gas to protect the filament from air which causes instant burn out when a rock places a small hole in the glass.

It is suspected rural car and truck owners quickly learned to stay their distance from the vehicle ahead with these new design seal beam. A flying rock causing a small hole in the glass can total the new sealed beam instantly.

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1955 and newer (above)

Beginning in 1955 both the 6 and 12 volt sealed beams have the three glass aiming bumps molded in the edges of the lens. The bumps were needed by new light aiming equipment provided to most all dealerships. These early second series GM bulbs with aiming bumps have the letters T-3 molded in the center of the glass lens. Most sold by the GM dealerships will also have the word Guide at the top of the lens.

Note: These modern bumps will interfere with properly attaching the chrome factory bezel on a 1940 Chevy/GMC headlight bucket as well if a 1937-1939 bulb light that has been converted to sealed beams. The bezels were not designed for the bulb still 15 years in the future. The 1940 GM vehicle owners will have a long hunt to find sealed beam bulbs without the three bumps.

It is interesting to note that the small two filament bulbs before 1940 had only a pair of contacts on their base. The bulbs were grounded by the metal reflector and the through the light housing.

A three wire plug was pressed to the seal beam in 1940 and newer. In this way the lighting had a ground wire which would carry the current to a solid metal part of the chassis. This gave less chance of a dimming light from rust or related corrosion at connection points.

Halogen Lights vs. Generator Charging

Wednesday, June 8th, 2016

With the introduction of Halogen headlights, night driving is a little safer due to more illumination. However, this improvement comes with a negative for those still using a generator for their electrical charging system.

To get the extra lighting from Halogen bulbs, the available amperage should be about 60. This will come from an alternator systems which has a charging ability of at least 75. If you are still using your original 6 or 12 volt generator, as was on most pre 1963 vehicles, the available amperage is approximately 45 at normal driving speed.

Therefore, with a generator charging system, there is not the amperage created to get the proper Halogen lighting. When at engine idle speed the lights dim much like the generator lighting systems. When at faster RPM, the advantage of Halogens is not reached.

Suggestion: Keep your original headlights when you have a 6 or 12 volt generator.

1941 Park Light Lens Retaining Bracket

Thursday, April 21st, 2016

A hidden lens retaining bracket was originally on all 1941 Chevrolet / GMC trucks. It holds the glass frosted lens firmly against the front of the park light housing.

After it’s over 70 plus years, the lens gasket has deteriorated, water has entered the housing, and the stamped steel bracket is rusted beyond use. Thus, so many 1941 truck owners are not aware that they existed.

General Motors made this sheet metal retaining bracket with no concern of it being rusted beyond use in 70 years!

The attached photos show a rusty but usable bracket in place still holding the lens in position. In this case, there are just a few pieces of the lens gasket still in position. The hole in the bracket allows for the threaded die-cast extensions to hold a screw that secures the top of the park light assembly.

Trivia: To save tooling money on the new 1941 truck, GM used the total park light assembly from the year before on the 1940 Pontiac car! Just another example of the GM truck division often given “pass-me-downs” from their cars of prior years. After all, trucks were for work and they did not need to be totally new each year to haul merchandise.

Surprise: Jim Carter Truck Parts is having this bracket reproduced. It will not be a money maker, however it seems it should be available for the 1941 owners.

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The Support Clip

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The Support Clip in Place

Before Sealed Beam Headlights

Thursday, March 31st, 2016

The pure sealed beam headlight bulb, as most know them, were not introduced until about 1954. Prior to this, a similar design was used on new cars and trucks beginning in 1940. It looked like a modern sealed beam but it was not. Unless you look close, these appear to be the later modern sealed beam. Actually there is a duel filament small bulb inside the assembly. Both nicely interchanged in most vehicles from 1941 and newer. Only 1940 first year is an exception in this design, at least on GM trucks.

The 1940’s headlight eliminated the more complicated light design from 1939 and older. These older units had a silver plated reflector that tarnished, a head light lens, a socket that secured the light bulb, and a non -metal seal to prevent air from entering the silver plated interior. In today’s world we often see this in domestic hand held flashlights that have a removable light bulb.

Almost all of the light bulbs during at least the early 1930’s had double filament headlight bulbs. They were 32cp (candle power) on either the low or high beam setting. This made replacing the burned out bulb a “no brainer”. You just pushed the bulb in the receiving socket and gave it a slight turn. This locked the bulb in place.

Even if you were 180 degrees different each time the bulb was added, it made no difference. Both high and low beam filament in bulb were 32cp.

NOW ENTERS A NEW VARIABLE. An aftermarket company introduces a new bulb with a brighter high beam! It is rated 32cp low and 50cp high. Better roads allowing faster driving needed a brighter high beam.

Because the original bulb receiving sockets remain the same, this new 32cp / 50cp bulb must be placed in the socket just right! The 50cp filament in the bulb MUST be aligned with wires from the main wiring harness. In other words, the high beam 50cp end of a modern light bulb must contact the high beam wire in the harness. (The bulb can only fit one of two ways) If incorrect you will have the 50cp as the low beam. Not good!

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1934-36 Duel Filament Bulb

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1937-39 Duel Filament Bulb

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6 Volt “Almost” Sealed Beam Bulb, 1940-1955

 

Headlight Reflector History

Friday, March 4th, 2016

Before the introduction of the sealed light headlight bulbs on automobiles and trucks the next best way of adding the most light was the use of reflectors behind bulbs. In this way most of the light was not lost. It was “reflected” to get the most light to shine in one direction.

(This method is still used today on many hand-held flash lights)

The shape of reflectors are designed to push the otherwise lost light into one direction so all become concentrated in a straight line. To get the most reflection in the 1930’s was to plate the surface with silver and then add polishing. This is still considered as the best in reflection and is rated as 100%.

Unfortunately, silver has a problem! It soon begins to oxidize (tarnish) as it combines with oxygen in the air. Headlight reflectors are at their very best the day they are polished. They slowly lose their quality after that day!

To help slow this oxidation, auto and truck manufactures placed a non-metal rim seal around the perimeter of the reflectors to lessen air flow. After a few years the seals also began to deteriorate and then oxidation continued. Of course, with each bulb replacement the outside air entered and oxidation was increased.

Much of this occurred during our country’s “Great Depression”. Little disposable income existed and replacing reflectors was almost out of the question. Fortunately there was little night driving and fewer vehicles, plus speed was so much less during the pre-World War II years.

NOW enters the modern technology of the 21st century! Reflectors can now be made with no oxidation at much less cost than repairing originals and having them silver plated. New coatings cover reflectors with a micro-fine spray on aluminum that give a 92% reflective quality of silver. Once sealed with a clear coating there is no oxidation! They remain at 92%.

NOTE: Two of these reflectors are available from Jim Carter Truck Parts and several of their full stocking early GM truck suppliers.

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1934-36 Chevy and 1936 GMC Truck. Part # LGL110, 8.25 diameter.  Available now uses 1929-34 32/32 candle bulbs
Part # LGL110 8.25 diameter

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1937-39 Chevy GMC Truck.  Use with halogen 12 volt
H-4 bulbs.  That are included Part # LGL109 7.5 ” diameter.

1934-36 Chevrolet 1/2 Ton Taillight Bracket

Wednesday, June 17th, 2015

Yes, it’s special only for this these three years. It lowers the license plate below the horizontal license bracket and attaches to the stake pocket. (This is not like the later 1937-38 bracket that raises the license above the horizontal).

This photo shows a pure unremoved bracket attached correctly to the left stake pocket (the taillight is an aftermarket) though bent from probably being hit on a fence post, one can see the bracket and how it once was. It even still has the correct metal loom and clip to secure it to the original oval taillight!

Good News! This special bracket (as well as the oval taillight, metal loom and clip) are now available from Jim Carter Truck Parts – 1-800-842-1913. Mention LGB230L for bracket.

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Original Left Taillight Bracket (See correct metal loom and its attaching clip)

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Incorrect taillight on correct bracket.

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Right side as looking toward rear of pickup

ADDITINAL COMMENTS:

A question has occasionally surfaced. Does the 1934-36 Chevy ½ ton have a different taillight bracket if the pickup came with a rear bumper than one without? When the pickup came without a factory bumper (as most did) then a standard taillight bracket was included. See Photo.

It was always attached to the left rear stake pocket, the normal place for all left hand drive GM pickups.

What if the optional rear bumper was added at the factory? Using the normal taillight bracket, the rear bumper covers most of the numbers on the license plate. It this correct?

Unless it is proved otherwise, we contend that the same bracket was used with or without a bumper. In checking a 1938 Chevrolet Master Parts Catalog, (what parts were available at that time to the dealer’s parts departments), there was also only “one” bracket available. Having the license partially covering the license plate numbers was probably of little concern to the new pickup owner or the state law enforcement officials. Remember, trucks were workers. They really got no further than the local neighborhoods or if used on a farm they might have an occasional drive to the local town! Road conditions were fair at best so the speed of these pickups was not an issue. Law enforcement personnel could easily catch up with a pickup. With no police radios yet available, police could not call in a license number to their headquarters!

1940-46 Map Lights, All Trucks Had Them!

Wednesday, December 11th, 2013

 Within 10 to 15 years the delicate factory three position light switch under dash usually broke.  Replacing this switch on a working truck in the 1940’s was usually not an option.  Now almost 70 years later few owners of these early GM trucks even know the light switch existed.  In most cases the little single filament light bulb and socket still remains hidden behind the middle of the dash panel.  A horizontal slot in the dash once allowed light to be emitted into the cab area.  Just right for reading a map!

NOW, they are once again available.   Various tooling was made so all parts of the switch would fit together.  One side illuminates the dash cluster, one side is for the map light and the middle position is off. Just like GM did it!  All 1940-46 Chevrolet and GMC trucks have the factory under dash holes for installation.  Contact Jim Carters Truck Parts at 1-800-842-1913 or check on line at www.oldchevytrucks.com. Mention item # EL157.  Price $29.50

 

Before Dual Filament Headlights

Thursday, April 11th, 2013


During the early years of automotive history, the invention of the dual filament light bulb had not emerged.  Therefore, there was no high and low beam headlight bulb on cars and trucks.  Only one beam existed for night driving.

This created a problem with the headlight beam from an on-coming vehicle on the narrow roads in town and country driving.  It was not until the late 1920’s that the two filament headlight bulbs came from the factory on new vehicles.

The attached photos show a great example of American Ingenuity sold in some vehicle parts stores during the 1920’s.  It is an electrical rheostat that allowed the driver to lessen the amount of light from the headlight.  This accessory was mounted on the steering column.  By moving the long lever with a finger, the driver could regulate bulb lighting.  How ingenious!  This very attractive assembly was recently found in an old trunk.   The unit is nickel plated as chrome was not yet available during these early years.  It is a very high quality part.

The price was $7.50, very expensive considering most workers made less than $1.00 per hour.   The sales company is shown to be the Universal Distributing Company of Tulsa, Oklahoma.

No doubt, the sales were limited due to the price but also because of a human trait.  Yes, the vehicle owner could lessen his light on the road but chances are good, the on-coming vehicle did not have one of these inventions.  The person that had spent the money on this accessory still received just as much light in his eyes from on-coming vehicles while he suddenly had less lighting from his vehicle!

Change-over to Sealed Beam Headlights in 1940

Friday, March 1st, 2013


In 1939 US auto and truck manufacturers realized the following year would be the introduction of the revolutionary new we call them “almost” sealed beam headlight bulbs.  These first “almost” seal beams were very unique by the newer standards 15 years later that most of us are acquainted with.  This early sealed beam assembly was much like the later design except it had a much smaller 2 filament light bulb inside.  Yes, the inside reflective plating was sealed inside with a glass fluted large lens that was now part of the total assembly.  This reflective coating was sealed from outside air and oxidizing did not occur.  There was no loss of shine with age.  It was one of the best improvements in safety since the introduction of bulb headlights.

A very interesting characteristic of these first “almost” seal beams:  A small hole from a flying rock did not burn out the unit.  The argon gas that protected the glowing filaments from quick burn-out was still inside the small internal bulb.

Red seal beam bulbs introduced in the mid 1950’s were different.  They were one large argon filled assembly.  When cracked by a flying rock, they instantly burned out.  Imagine the number of new designed sealed beam bulbs that were lost by vehicles driving at high speeds on gravel roads behind other vehicles!  There must have been a run on the old style obsolete units in rural areas.

The 12 volt sealed beams were not made with the early design “small in the reflector” design.

For most car and truck manufacturers it was too late to do a major redesign of the headlight assemblies for the 1940 year.  Chevrolet and GMC trucks reshaped the metal edge on the 1939 bucket so the new seal beam bulbs fit perfectly.  For those not having a detailed eye for auto and truck changes, it would probably never be noticed.

For those buying a new 1940 vehicle after driving with the old style reflector bulb design, it would be the most significant change in years.  The gradual diming of their lights over the years as the silver reflector tarnished was now history.  Yes, the owner could have removed the glass lens from his older vehicle, polished the silver plate, and reassemble; however it would be like today; most drivers would not take the effort.

Below are photos of the earlier 1937-39 headlight and the new 1940 redesigned for the new seal beam.  The visible part of the buckets is identical including the chrome rings.  It’s only the hidden edge for the “almost” sealed beam bucket that is different.

 


1940 Sealbeam bucket

1937-39 and older headlight-reflector bucket

1940 “Almost” Seal beam Headlight

1937-1939 and older Headlight

“Almost” Seal Beam front

“Almost Seal Beam side

“Almost Seal Beam metal back

1936-46 GMC Taillights

Monday, July 2nd, 2012


1936-46 GMC Taillights

Though things were shared between GMC and Chevrolet trucks, General Motors made sure many items remained very different during the early years.  GMC preferred very few things to be similar to Chevrolet. Their customers needed to see an almost stand-alone truck with the higher price of the GMC.

One very obvious difference is the change in taillights. There is no comparison to Chevrolet. The massive GMC stamped steel one piece bracket combined with a redesigned 4 inch taillight makes the pair a “one of a kind”.  They do not interchange with Chevrolet during these years.

Finding any of these parts during a total 1936-46 GMC pickup restoration has become almost impossible. It is said a shop is attempting to remake the bracket, however, if that happens the taillight will be almost as big of a project to get. The light is not being reproduced.

Hint: This taillight was also used on Chevrolet, Buick, Oldsmobile station wagon tailgates from about 1949 through 1952.  Therefore, you will see more lights than GMC brackets at swap meets.

1936-46 GMC Taillights 1936-46 GMC Taillights
1936-46 GMC Taillights 1936-46 GMC Taillights

Same tail lights on early GM Wagons!

1941-1946 Park light and Headlight Assemblies

Monday, June 20th, 2011


At the beginning of the 1941 Chevrolet and GMC truck body style, the parking light assembly was placed on top of the headlight bucket.  This was the first time both were placed on the fender as a pair.  All worked well together.  To save tooling costs, GM chose to add a pre-existing assembly from the year before on the 1940 Pontiac car.  No changes were made from this Pontiac park light assembly except its long sheet metal top was now painted and not chromed.

Overseas during World War II, when civilian front fenders were used on GM military trucks (instead of the more famous flat fender ‘army truck’ style) General Motors created a parking light that emitted a small strip of light to be seen at a shorter distance.

Beginning in 1942 and continuing through mid 1947 (when this body design was discontinued), GM used a much less expensive park light housing on civilian trucks.  A one piece stamped metal cover was attached to the headlight bucket for a fraction of the cost as in 1941.  This also used a smaller less expensive glass lens.

Therefore during this 6 ½ year truck production (1941-Mid 1947) the same headlight buckets were on Chevrolet and GMC trucks.  The difference was their hole punching which adapted to changes in parking light assemblies.

1942-45 Military

1942-45 Military

NOTE:   THE 1941 PHOTO WILL FOLLOW SOON

Early Park Light Assemblies

Thursday, February 11th, 2010

The introduction of factory sealed beam headlights came to the automotive industry in 1940. It was then necessary to create park light assemblies. (They could no longer be incorporated in the bulb and reflector style headlight as before).

To some, the first 1940 GM assemblies were simply “add-ons”, maybe a quick design due to the fast industry acceptance of the new sealed beam system. They sat on the front fender away from the headlights and were the same on Chevrolet and GMC trucks as well as Chevrolet cars. Right and left are identical.

By 1941 GM engineers had developed park light assemblies to flow more with the body lines. Most every GM vehicle had a newly designed unit. The exception was the Chevrolet and GMC trucks. Whether to save money or there was not time, GM’s 1941 commercial vehicles were given the same park light assembly as used on the Pontiac car the year before. These 1940 Pontiac assemblies secured very nicely to the top of the long truck headlight bucket in 1941 and provided the more modern look.

By 1942 GM trucks were finally given their own park light assemblies. They were similar to the 1940 Pontiac design but were more basic. What had required four die cast pieces with the early Pontiac style now could be accomplished with one stamped sheet metal cover. This of course, required a subtle change in their glass lenses. This 1942 design was continued through 1946.

Early Park Light Assemblies

1934-1946 GMC Tail Lights

Thursday, February 11th, 2010

Early GMC Tail Light

Though items were shared between GMC and Chevrolet trucks between 1936 and 1946, General Motors made sure many parts remained very different during the early years the GMC preferred very few things to be similar to Chevrolet.  Their customers needed to see an almost stand-alone truck with the higher price of the GMC.

One very obvious difference is the change in tail lights.  There is no comparison to Chevrolet.  The massive GMC stamped one piece steel bracket combined with a redesigned 5-inch tail light makes the pair a “one-of-a-kind”.  They do not interchange with Chevrolet during those year.

It was not until the new body style in mid 1947 that the two brands shared tail lights. When the larger GMC’s 5-inch light was discontinued on trucks in 1947, Chevrolet introduced it on their 1949 through 1952 station wagons and early GMC buses. It was placed in the center of the gate and was the only factory light on the vehicle.

Even though 1936-1946 taillight was used for so many years, it is becoming very difficult to find. Most GMC pickup restorers use the reproduced Chevrolet rectangular design and only a few GMC perfectionists are aware that there is a difference.

A shop in the US is attempting to remake this bracket; however, if this happens the tail light will be almost as big of a project to find.  It is not being reproduced.

Hint: This tail light also was used on Chevrolet, Buick Oldsmobile Station Wagon tail gates from about 1949 through 1952.  Therefore you will see more lights than GMC brackets at swap meets.  See Photos

1934-1946 GMC Tail Lights 1934-1946 GMC Tail Lights 1950 chevy taillight 1951 old taillight

6 Volt (Not Actually) Sealed Beam Bulbs

Thursday, February 11th, 2010

Two major changes occurred in 6 volt General Motors sealed beam bulbs (are actually not sealed beams) since they were first installed on vehicle assembly lines in 1940. The perfectionist restoring his truck to exact original specifications must have the correct headlights for his year. In very competitive judging, it’s these details that can make a difference. No doubt, replacement bulbs from a GM dealership with slow sales could sometimes be placed on newer vehicles a few years after the units were discontinued, however this article is based on bulbs you would have bought new from the factory during that particular year.

1940 through about 1955 – These headlights had a double filament small bulb built inside. The large glass reflector in the back was sealed from the elements.  It stayed bright even after the inside bulb burned out.  It was not like earlier open reflectors that could tarnish with age due to the silver plating.  The assembly comes with a metal black back attached for support. If the outer glass gets a rock hole, the light continues to work well. The filament is still encased in the smaller argon gas filled glass assembly (see photo).

6 volt bulb

1940 through about 1946 (above)

About 1955 and Newer (below)

The first truly  sealed beam bulb, as we know it, was introduced about 1955.  Between the reflector and the outer glass covering is the open unprotected filament (no small internal bulb). The total interior is filled with argon gas to protect the filament from air which causes instant burn out. When a rock places a small hole in the glass there is instant burn-out

One of the big visible differences in this first series sealed beam bulb and today is there are the three aiming bumps on the outside in about 1955. The bumps were necessary when using the new dealer aiming equipment.

1955 and Newer 6 volt bulb

1955 and Newer (above)

Beginning in 1955 the 6 and 12 volt sealed beams have the three glass aiming bumps molded in the edges of the lens. The bumps were needed by new light aiming equipment provided to most all dealerships. All of these GM bulbs with aiming bumps have the letters T-3 molded in the center of the glass lens. Most sold by the GM dealerships will also have the word Guide at the top of the lens.

Note: These modern bumps will interfere with properly attaching the chrome factory bezel on a 1940 headlight bucket as well if a 1937-1939 bulb light that has been converted to sealed beams. The bezels were not designed for the bulb still 15 years in the future. The 1940 GM vehicle owners will have a long hunt to find sealed beam bulbs without the three bumps.

4 Speed Back Up Light Switch

Thursday, February 11th, 2010

Four Speed Backup Light Switch – They Did Exist!

4 Speed Back Up Light Switch

The first design of the 4-speed synchronized truck transmission, introduced in 1948, was used through about 1965. About mid series, when the dealer installed backup light increased in popularity, a special switch was attached to the base of the floor shift lever. This was the only location possible as there is no external linkage on a 4-speed.

No doubt regular floor contact with shoes and boots shortened the life of this small electrical switch.

Buy Parts for 1934 to 1946 Trucks