Until sidewinder locks and transponders appeared on the scene, automotive lock systems had remained unchanged for more than 60 years. The last big change in auto lock designs was probably the GM locking sidebar system and that first appeared on 1936 GM models.
Pin tumbler lock systems were popular during the 1920s with manufacturer names such as Yale, Sargent, Corbin, Russwin and Eagle leading the way. Wafer locks were used even before 1920. Early wafer-type auto locks used double-sided keys, but the use of bi-directional double-sided keys had to wait until 1965 when Ford introduced their double-sided pin tumbler lock systems.
Chrysler and Ford began using pin tumbler lock systems in the 1930s. During this same period, many of the smaller companies such as Nash, Hudson and Packard used Briggs & Stratton five tumbler wafer locks. With the exception of Chrysler locks, most car locks made from 1935 to 1970 had key codes printed somewhere on the cylinder housing. Aftermarket key manufacturers still produce key blanks for 95 percent of these old cars and key codes are readily available.
Ignition and door locks were generally keyed alike. Trunk locks and glove box locks were keyed alike but used a separate key code. Chrysler was the exception. A third key was used for locking Chrysler glove box locks which had a wafer lock with a 1098X keyway. Another exception was GM Chevrolet and Buick models in the 1950s. These two models used a key system with all locks keyed alike.
1933-34 Omega key blanks are no longer made, but every car key blank used since 1935 is still listed in the Ilco key catalog. Depending on the Chrysler model, Ilco 1199, 1199A, 1199AR,1199B,1199C,1199D,1199DR and 1199E were used from 1935-1938. Chrysler standardized on a “BP” code series using the Ilco X1199B keyway from 1939-1946. Chrysler used a “CA” code series from 1947-1948 but still used the X1199B keyway. From 1949-1955 Chrysler used a “CB” code series with the Ilco X1199G keyway. From 1956-1967 Chrysler used a “CJ” series with the Ilco X1199J keyway.
Some Chrysler models during 1959-1965 used a “CV” series, GM-type sidebar trunk lock with an Ilco 1759P keyway. Steel shafts on Chrysler T-handle locks in the late 1940s and early 1950s were notorious for separating from the die case handle portion. Chrysler models in the late 1950s used push button trunk locks. There were many different designs and sizes. Most were not made to be easily disassembled. Impressioning is the best choice when key fitting.
GM experimented with a double-sided key system for 1934-1935 and key blanks are no longer made. From 1936-1966, GM used a six-cut sidebar lock system with Ilco key blank H1098LA and code series 8001-9499. A set of 60 tryout keys was available to unlock these sidebar locks. The ignition lock has a poke hole in the facecap. Turn the ignition counter-clockwise to the accessory position using a proper tryout key. Insert a pin or bent paper clip into the poke hole to depress the retainer, then turn the cylinder slightly further counter-clockwise and remove the cylinder. Key codes are stamped on the plug.
GM door locks from 1936 to 1949 used an exterior retainer clip which was located under the door weather stripping. Pry the retainer outward with a screwdriver and the lock cylinder can be easily removed. Key codes are stamped on the housing. GM changed to a pushbutton door handle in the 1950s which had the cylinder mounted in the push button. A large retainer hidden behind the outer weather stripping was used. After dislodging the retainer, the door handle can be removed. Key codes are stamped on the shaft extension.
While GM has used many different glove box lock shapes over the years, many of them have a similar basic design. Picking skill is required. The lock must be in the unlocked position. If it is locked, pick and turn the plug clockwise one quarter turn. Next, compress the locking bolt downward as far as it will go and simultaneously pick the plug clockwise one quarter turn. The plug can now be removed. Key codes are printed on the side of the lock plug.