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.
In 1967 GM changed their lock system, adding one more depth and began using various lettered keyways. Key codes were stamped on lock cylinders until the early 1970s. After that time only the ignition lock contained a key code.
Model A cars were made from 1927-1931. One of the most popular keys for Model A vehicles is the Ilco C1098A. For some reason Ilco shows this in the General Motors section, but it is definitely only for Ford Model A vehicles.
Ford began using Hurd locks in 1932 and carried the same Ilco 1125H keyway through 1951. Various Dodge trucks also used the same keyway for many years. Several different code series were used such as FX, FW &FY. Fortunately Ford printed the code numbers on every lock, so Ford key fitting is not too difficult. Door locks were held by a set screw accessible on the edge of the door. Unfortunately these screws often rust in place, so removing a Ford door lock is always an adventure.
Ford was one of the first car manufacturers to use locking steering wheels. Vehicles from 1932-1948 used this system. The ignition lock is retained by a serrated pin located on the bottom of the steering wheel lock unit. Removal can be done by drilling a hole into the serrated pin and tapping the hole for 6-32 threads. Insert a long screw into the tapped hole, then attach a vise grip to the screw at a right angle. Hold onto the vise grip handle and hit the vise grip near the screw with a hammer, A few swift hits should dislodge the serrated pin. The ignition cylinder can then be removed for key fitting.
Many Ford locks had no shoulder on the front of the plug. A shim can often be inserted in the front of the cylinder and tumblers can be lifted with a pick as the shim is moved towards the rear. This system can also be used on Hurd padlocks.
The small pin size of Ford locks sometimes lead to quick wear and failure. To solve this problem Ford changed to a sturdier key system for 1952-1956 (Ilco 1127D). Ford again changed keyways for 1957-1966 and added various grooves. An Ilco 1127DU blank will operate any ignition/door lock and the 1127ES will operate any glove/trunk lock made from 1952 to 1966. Key codes continued to be stamped on most lock housings through 1966. Many truck models continued to use the Ford single-sided lock system into the 1970s, but most other Ford models changed to the double-sided Ilco 1167FD key system in 1967.
Early Studebakers from the 1931-1940 used wafer keys and keyway O1122A. 1941-1949 models used an X1199AR blank for the door and ignition with the O1122A keyway continuing for trunk locks. 1949-1952 models often used Hurd locks with the same Ilco 1125H keyway as 1932-1951 Ford. Studebaker went back to the X1199AR blank from 1952-1965. Ilco O1122A blanks were used during 1952-1965 for trunk locks.
Compared to all other cars on the road, Studebakers of the 1950s caused the most headaches for locksmiths. Door cylinders are held by an internal retainer. The door skin is so narrow that a human hand cannot get inside to reach the retainer. A special tool is needed to access the retainer from above after removing the outer door handle. Another problem is the door/ignition depth and space system. An unusual .018 depth increment is used with depth #1 starting at .222.
Most of the other popular cars of the day such as Hudson, Nash, AMC and Packard all used Briggs & Stratton five wafer keys exactly the same as big trucks are using today. If you have 1098X, 1098L and 1098DB key blanks on your board, those will cover almost every one of the lesser car manufacturer models. Although a thin blank such as an Ilco 1098M will enter all of these keyways, individual blanks are a much better choice against possible breakage.
Most of the door locks used during the 1930s were called pillar locks. These locks had long square shafts connected to the cylinder. The shafts had flexible couplings. A guide hole was drilled into the rear of the shaft.
Locksmiths would poke a small hole into the upholstery in line with the locking hub and insert a thin wire through the hole and into the guide hole in the lock shaft. The cylinder could then be easily inserted into the door while the shaft was guided into the lock hub. Since the upholstery was made of thick cloth or mohair, the small hole was never visible.
Brass was the material choice for auto locks in the 1920s, but diecast took over in the 1930s. I guess nobody ever expected that those old diecast car locks would still be in use 80 years later. Before fitting keys to any old diecast auto lock, insert the tip of a key a short distance into the plug and wiggle the plug left and right. If there is plug and tumbler movement, chances are the lock is still operational. If the plug is ‘frozen’ in place, you have a problem. Another indication is if the plug has wrinkles on the surface. The wrinkles indicate that the diecast material is disintegrating with age. Any turning pressure such as during impressioning can cause further disintegration and in the worst case the plug will break into small pieces. If the plug is not loose in the housing, there is not much you can or should do.
All cars made during the 1930s had clutch and brake pedal connections which extended through holes in the floor boards. When there was a lockout, old time locksmiths would lie on the ground and insert a long rod with a hook at the end through the floor board holes. The hook on the rod was then used to grasp the inner door handle and unlock the vehicle.