Frequently Asked Questions


Where are you located & what are your hours?

We are located in Houston Texas and are near Hobby Airport. We are open from 8AM-5:00 PM CST Monday thru Friday. For directions to our location please click here.

What do you sell?

Gilmore Global Instruments specializes in instrumentation made to monitor or control an engine. To view our most common product lines click here. If you are looking for something that you do not see on our product lines page feel free to give us a call. We specialize in finding just the right instrument for customer applications.


I want to buy a new gauge. What do I need to do?

When ordering a new unit, it is best to have a part number ready. Normally, most manufacturers will list the product’s part number somewhere on the unit. If you cannot find a number, it is still a good idea to have as much information about the unit as possible. If you need help researching your product you can view our product catalogs here, or just give us a call.

Once we have identified your unit, we can then get you a new one.

My gauge/tachometer/speedometer isn’t working. Can you fix it?

That one seems to be everyone’s favorite question. In short, we can solve your problem. If the instrument is installed incorrectly, or if there is a compatibility issue, we can most likely resolve it. If your gauge is broken we will most likely replace it.

If you are trying to hook up an instrument, but you need some help, check out our help page and our video Gauge basics

I don’t want a new gauge; I want you to fix this one!

Gilmore Global Instruments has repaired instruments since the 1950’s. We certainly have the capability to repair a lot of instruments, but these days it actually tends to be more cost-effective to replace the instrument instead of repairing it. That said, we can fix your instrument, but it depends on exactly what you have. Many old speedometers and tachometers cannot be repaired because the parts to do so are either unavailable or completely nonexistent.

My voltmeter has 3 terminals on it! How do I hook it up?

Voltmeters only use the positive (I) and ground (G) terminals. Datcon and Stewart Warner voltmeters can sometimes have a third stud in the signal (S) spot. You can ignore the signal terminal. Datcon and Stewart Warner gauges are mass-produced, and the third terminal is simply an artifact left over from the production process. The factory will normally cut the unneeded stud off.

I've got a very old Stewart Warner gauge. Do you have any information on it?

Stewart Warner has manufactured instruments since 1905, so there are a lot of old units floating around. Gilmore Global Instruments has spent a lot of time & energy building a library of old Stewart Warner catalogs and technical manuals. We have some of the most popular and difficult to find catalogs hosted on our website. Click here to view the catalog page and scroll to the bottom to find the old Stewart Warner catalogs.

How old is my Steward Warner Gauge, and what is a code date?

If you’re trying to figure out how old your item is, you will need to check the code date. The code date will typically be printed somewhere on the unit itself. Since 1905 the date system used by Stewart Warner has undergone a number of revisions. Below you will find out how to identify your instrument’s date.

1994 and Earlier: The housing of the gauge itself should have a set of alphanumeric characters printed onto it. For example, you might see 970B M8. 970B tells us that this unit was a pedestal mounted tachometer and the M8 reveals that the unit was made in August of 1968. Even though letters may have been used multiple times over the years, the appearance of the unit will typically indicate which era the unit came from. For example, M was used in 1920, 1944, 1962, and 1992, but the appearance of the gauge will vary drastically depending on which era it came from.

Post 1994: Since 1994, most Stewart Warner instruments have had the code date printed on a sticker which is put onto the housing of the unit. This code date is typically printed perpendicular to the printed part number on the label. The code date itself will consist of 4 numbers. The first 2 numbers will indicate the year and the last two will designate the month. For example, 0307 will indicate the unit was made in July of 2003.

Notice: In 1994 when the code date system was changed, both systems were used for several months until the changeover was complete.

Months (Since 1994 a zero has been used in front of months with only one digit: 1 - January became 01)
1 - January
2 - February
3 - March
4 - April
5 - May
6 - June
7 - July
8 - August
9 - September
10 - October
11 - November
12 - December


A - 1909

A - 1933

A - 1957

A - 1981

B - 1910

B - 1934

B - 1958

B - 1982

C - 1911

C - 1935

C - 1959

C - 1983

D - 1912

D - 1936

D - 1960

D - 1984

E - 1913

E - 1937

E - 1961

E - 1985

F - 1914

F - 1938

F - 1962

F - 1986

G - 1915

G - 1939

G - 1963

H - 1987

H - 1916

H - 1940

H - 1964

J - 1988

J - 1917

J - 1941

J - 1965

K - 1989

K - 1918

K - 1942

K - 1966

L - 1990

L - 1919

L - 1943

L - 1967

M - 1991

M - 1920

M - 1944

M - 1968

N - 1992

N - 1921

N - 1945

N - 1969

P - 1993

P - 1922

P - 1946

P - 1970

R - 1994 OR 94

Q - 1923

Q - 1947

Q - 1971

S - 1995 OR 95

R - 1924

R - 1948

R - 1972

T - 1996 OR 96

S - 1925

S - 1949

S - 1973

97 - 1997

T - 1926

T - 1950

T - 1974

98 - 1998

U - 1927

U - 1951

U - 1975

99 - 1999

V - 1928

V - 1952

V - 1976

00 - 2000

W - 1929

W - 1953

W - 1977

01 - 2001

X - 1930

X - 1954

X - 1978

02 - 2002

Y - 1931

Y - 1955

Y - 1979

03 - 2003

Z - 1932

Z - 1956

Z - 1980

04 - 2004

For years after 2004 you would find the last two digits of the year used as shown in the table above for any dates 1997 onwards.

Note: The letters I and O are not used. In the last column the letters G and Q were not used.

I've got something, but I have no idea what it is. I just need another one.

When trying to identify and replace an old or unknown item your best bet is to gather as much information about the item as possible and then call us. Be sure to tell us what part numbers, if any, are listed for the product, what its application is, and what it came out of.

Control Cables

What is a control cable?

A control cable is a device used to transfer a linear or rotary motion. When you push, pull, or twist one end, the other end will also perform the same action. This allows for an operator or application to transfer mechanical force from one area to another. Cables are used in a number of different applications include brakes, throttles, accelerators, valve control, and more.

I need a new cable. Build me one.

There are many different ways to build a control cable, and we must first identify it before we build it. There are two main ways to do this. The first way is to examine the product catalogs for cables, and tell us the part number that you want built. Click here to head to the control cable product page. On that page you will find some part number builders that help you determine exactly what it is that you need.

The second manner is to bring it to us or ship it to us, and we will identify it for you. Once we’ve identified your cable, we can then construct you a new one.

My cable broke. Can you fix it?

In short, not normally. Most cables cannot be repaired, only replaced. This is as much a safety concern as it is a technical one. Aside from the difficulty of repairing certain types of breaks, cables are sometimes not as strong after repairs raising safety concerns.

Flexible Shaft Cables

What is a flexible shaft cable?

Flexible shaft cables are devices used to translate a rotary motion across a specified distance. Basically, if you have an application that is spinning, and you want to transfer that spin to another location a flexible shaft cable should be used. Flexible shafts are most commonly used in applications involving tachometers and speedometers. Flex shaft cables can be built in thousands of different styles.

I need a new flex shaft. What will it take to get one?

If you need one built, the easiest way to identify it is to bring it in to us so we can get our hands on it. If we are unable to see it in person, you could give us the exact dimensions, thread sizes, drive key sizes and so on. Once we know exactly what it is, we can then build it. For more information on flexible shaft cables please click here.

Ratio Adapters/ Right Angle Drives

What is a ratio adapter?

A ratio adapter is simply a housing that contains a set of gears. This housing will have an input port and one or more outputs. These outputs will spin at a given ratio in relation to the input. For example, a 2:1 ratio means that for every 1 time the input is turned the outputs will spin 2 times.

Ratio adapters are available in a wide variety of styles, ratios, and sizes. Most commonly used to change the rotational speed of an application, ratio adapters are also used to link flexible shaft cables together at a right angle. Please click here for more information about ratio adapters.

I need a new adapter. What do I need to do to get one?

Because adapters come in so many styles, we first need to identify what you need. If you have an old unit you can bring it in to us, or you can try to identify it yourself using our adapter catalog found here.

Once we’ve identified it, building and shipping the adapter is a fairly straightforward process. Gilmore Global Instruments is the owner of the Reliance / MassTech product line which was established in 1908, and we’ve personally built adapters since 1950. We’ve designed many different adapters over the years, and we continue to modify the product, as needed, for customers. If you need an adapter, give us a call.