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Speedometers and Guages

1947-53 Gauge Mystery

Thursday, May 24th, 2012

We ask our readers: What is the correct color for the letters and numbers for the 1947-53 Chevrolet truck dash gauges? Were they white? Have they slightly yellowed after 50 years and now have a more cream color?

Our company has made the decals both with white and slight yellow hue. We had assumed the originals have slightly yellowed with age. See photo.

I welcome your opinions at jcarter@oldchevytrucks.com

1947-1953 Guage Mystery

Speedometers to Go…

Monday, August 15th, 2011

Rebuilt Speedometers for Chevy Trucks & GMC Trucks


Quality Rebuilt Speedometers

When your older truck needs a rebuilt speedometer, think of us! Our company, in combination with a local specialized shop, provides a quality product that you will be proud to place in your vehicle.

With most new repair parts, no longer available, we obtain used speedometers from across the country. Only the best parts are removed. These are combined with available new components to create a quality finished product. The following photos show various stages in the repair process.

Speedometers

Work Bench

Parts Inventory

Finished Products

Advance Design Speedometers

Thursday, February 11th, 2010

No less than five speedometers were used in Chevrolet trucks during the Advance Design years, 1947-1955. If you want your truck just right, be sure you understand the differences. Restoring one you have on a shelf or purchased at a swap meet may not be proper for your year. The following will provide a description of differences.


1947 speedometer

1947

Red-Orange needle. Lower two tabs 4 3/4″ apart. 80 MPH (A clear needle means the color has faded away.)


1947 speedometer

1948

Red-Orange needle. Lower two tabs 6″ apart. 80 MPH


1947 speedometer

1949-1951

White needle, lower two tabs 6″ apart. 80 MPH


1947 speedometer

1952-1953

White needle, lower two tabs 6″ apart. 90 MPH


1947 speedometer

1954-1955

Totally different from earlier years. Silver needle over black face. Few parts interchange


Then there is the GMC speedometers used during 1947-1955 (Only 1952-1953 are the same.) That is another story!

Advance Design Gauge Cluster

Thursday, February 11th, 2010

The Chevrolet “Advance Design” gauge cluster looks much the same between 1947 and 1953, however a few differences do exist. For the perfectionist, these changes are important.

In 1947-1948 the gauge needles are short (5/8 inches) and painted red. Between 1949-1953 the needles become longer (3/4 inches) and are white to match the change in the new speedometer needle.

The other variable is the temperature gauge. Though not calibrated different, its numbering changes from a maximum of 212 degrees to 220 degrees in 1953. With anti freeze and now a pressure radiator cap, fluid could reach a higher boiling point than 212 degrees.

1954 Speedometer

Thursday, February 11th, 2010

1954 speedometer 1

When looking closely at the black 1954 Chevrolet speedometer face, a small 1/8 inch diameter round hole will be noticed at the top and bottom.

Owners of 1954 trucks will always be acquainted with the top hole. This emits red light to notify the driver that the high beams are on.

Most are not even aware of the existence of this lower hole. Look closely. It’s always on the 1954! It is placed there to emit a flashing green light when the optional turn signals are added. Prior to this model, the GM trucks add-on turn signal head was clamped to the steering column. With the turn signal on, a small light would blink in the head.

In 1954, the optional turn signals became ‘built-in’ the column below the steering wheel. The blinker light became a part of the dash like later vehicles.

When the factory or the dealer added optional 1954 turn signals, the little hole with green tape inside was ready for the new dash bulb. This one flasher light would blink if the signal was to the right or left.

1954 speedometer 2

1951-1953 Gauge Cluster Differences

Thursday, February 11th, 2010

1951 1953 guage cluster 1

On first glance, most people assume that both Chevy and GMC gauge clusters are fully interchangeable and are the same except for perhaps the minor difference with Chevy oil gauges topping out at 30 psi versus GMC gauges maxing out at 60 psi. But that’s quite a bit short of what the actual differences were originally! There are actually no less than five distinct differences in the same year gauge clusters when taken from same size trucks. Below you will see two examples of late 1951 to 1953 gauge clusters; one on the left from a Chevy truck, and the one on the right from a GMC truck. Before you start jumping up and down about the tan background brown letter gauges in 1951, realize that the gauge clusters changed in late 1951 and then stayed brown background cream letters up through 1953. The first and most obvious difference is the oil gauge, but upon closer inspection you’ll find twelve distinct differences between them; six on each gauge cluster.

  1. GMC oil gauge reads 60 psi while the Chevy oil gauge tops out at 30 psi
  2. GMC used an Ampere gauge showing 50- | +50 where Chevy used a C | D Charge/Discharge style gauge
  3. The label under the electrical gauge on Chevy clusters says simply “BATTERY” while on the GMC it says “AMPERES”
  4. GMC temperature gauges maxed out at 220F where Chevy temperature gauges stop at 212F until 1953. In 1953 Chevrolet matched GMC with 220F
  5. The GMC fuel gauge was used for both big and small trucks, so it reads “FUEL” where the Chevy gauge reads “GASOLINE” since there were no Chevy diesel trucks at that time
  6. The Chevy gauges all have longer 2/3rds way needles than the GMC gauges with half-way needles

So the next time you’re shopping for gauges, these subtle differences may help you to better understand what you need whether you are driving a Chevy or a GMC.

Rob English

www.oldGMCtrucks.com

1947 Speedometer

Thursday, February 11th, 2010

One of the numerous differences in the new 1947 Advance Design trucks is the different position of the mounting tabs on the speedometer. Reasons for doing this on both Chevrolet and GMC are as follows: with the introduction of this body style in mid-1947, both 3 and 4 speed transmissions were the floor shift design. However, in 1948 with the introduction of the 3 speed column shift transmission, the new shift linkage was now parallel and above the steering column. The distance between the two lower tabs on the speedometer case was widened from 4-3/4′ to 6′. This got the tabs away from the new shift linkage.

The person restoring a 1947 Chevrolet or GMC should be aware of this change. If he turns in his speedometer core to a re-builder on exchange, chances are good he will not receive a 1947 style in return. Few, if any, re-builders will notice this tab repositioning and will exchange from their stock!

1947 speedometer 1

1947 Left | 1948 Right (above)

1947 speedometer 2

1947 Left | 1948 Right (above)