Installing the 1929-1940 Steering Mast Jacket Bushing
By Stephen Kassis
The steering mast jacket bushing with horn wire for 1929-1940 Chevrolet cars & trucks often needs to be replaced. The new bushings are made with a urethane outer shell with a nylon center bushing. It is a much improved design over the original GM part due to modern materials used to make it.
This bushing can be installed in a few hours. The first step is to disconnect the battery. Disconnect the horn wire connection at the base of the steering column (on 1929-1930 models directly at the horn).
Next, remove the steering wheel. Start by prying the horn button out of the hub on the steering wheel. The horn button has a rubber base with inset “S” shaped wire contact, covered with a metal cap. Stick a small screwdriver under the edge of the horn button and pry it up, then pull the button and contact wires out of the hub. This will expose the nut at the end of the steering shaft. Check the condition of the rubber button as these are often collapsed and should be replaced.
The steering wheel is held by a nut onto a tapered shaft. Loosen the nut until it is flush with the top of threads. Spray a little penetrating liquid on the center hub area. Pull up forcefully on the steering wheel while a second person strikes downward on the shaft & nut with a brass hammer. If this does not dislodge the steering wheel from the shaft, it may be necessary to tap the horn wire holes in the hub of the wheel and remove it with a steering wheel puller. This will require a 10-24 tap and a couple of long 10-24 bolts with washers.
To remove the old bushing, you must remove the tube from the steering column. With the steering wheel removed, loosen the clamp at the base of the steering shaft tube. Remove the clamp holding the steering tube to the dash. Slide the tube off the steering shaft. Note: use caution when removing the steering shaft tube as it must be slid into the passenger compartment and may get grease or oil on the upholstery or headliner. In rare cases, it may be necessary to remove the steering box to get the tube off the shaft.
The operation of the horn requires a set depth of the bushing brass ring in the column tube. The upper part of the sheet metal steering column housing has a punched hole which is designed to stop the bushing when inserted into the tube. The new bushing can then be inserted to the same depth, insuring proper positioning of the bushing to the brass ring. Keep in mind that the tube can be adjusted up and down when installed to adjust the bushing contact with the horn wires.
A blunt ended rod or stick (such as a broomstick or heavy walled PVC pipe) can be used to tap out the old bushing. With the broomstick on the ground with the tube over the top, use a slide hammer action downward to drive the bushing up and out of the top of the tube.
Installation requires lubrication with soapy water, silicone or a mineral oil based lubricant. CAUTION: Use eye protection when driving in the new bushing. A large 1/2″ drive deep socket (with extension), slightly smaller in diameter than the tube, is an excellent tool to drive in the new bushing. Use the blunt end of the socket against the bushing (this means putting the socket on the extension reverse of normal, so the smooth, large surface is toward the bushing). If a socket and extension are not available, you could also try a heavy walled PVC pipe with a coupler on the end that is the same diameter as the bushing. It is critical that the force of driving the bushing in place is spread over as much of the bushing surface as possible. Do this on a piece of hardwood so there is no damage to the shape of the steering column tube.
Measure the outside diameter of the new bushing and compare to the inside diameter of the tube. The new bushing is made slightly larger so it will fit tightly in the old tube. The bushing must fit tightly in the tube so it will not turn. However, this can make the installation difficult. If the fit is too tight, it may be necessary to sand the OD of the bushing slightly. Apply lubricant to both the inside of the tube and outer edge of the bushing.
To install the bushing, slide the wire into the tube from the top and thread it through the hole on the side near the bottom of the tube. Find a small grommet to protect the wire as it passes through the sheet metal tube. Start the bushing into the tube and push it into the proper position. There is a dimple pressed into the side of the tube to stop the bushing from going too far. Don’t force the bushing past this point. Using body weight is usually sufficient to seat the bushing. If additional pressure is required, light tapping on the installation tool can be used. Take care not dent or bend the brass plate. Denting or bending of this plate will result in poor horn performance. The bushing is tough, but with too much force, it can be damaged.
Before installing the tube and bushing assembly, it is important to check the steering shaft where the new bushing will ride. Often, the old steering shaft will be pitted or rusted in this area. The shaft must be smooth to get the best operation out of the new bushing. Use sandpaper or emery cloth to smooth this area. Lubricate the area with light grease and install the tube onto the steering shaft, upside down – bushing side first, to check for fit. If there is a tight spot, continue to smooth the shaft until there are no rough spots causing the shaft to bind against the bushing.
Remove the tube and move to the work bench. Install a rubber grommet in the hole around the horn wire. This should make a snug fit for the wire and also protect it. Pull the wire until there is no slack. This will prevent the horn wire from rubbing on the steering shaft during operation.
Reinstall the steering tube onto the steering shaft, check for fit once it is in place. Seat the tube into the steering box clamp. Assemble the steering column clamp back onto the dash mounting but leave it loose for now. Install the steering wheel, making sure the woodruff key and keyway are lined up. Insert the metal trim cup in the wheel and tighten the nut. Connect the horn wire at the base of the steering column.
Check the rubber horn button to insure that it is not collapsed. This would cause the horn to honk when it is not desired. Install the horn button rubber with metal cap and horn contact “S” wire. Push the shoulder of the rubber button down into the trim cup with a small screwdriver until it is evenly seated.
Connect the battery. Check the horn operation by pushing down on the horn button. If it does not honk, it may be necessary to pull the steering tube up closer to the base of the steering wheel. Tighten up the clamp at the base of the steering tube and also at the dash. Re-check the horn operation.
If the horn honks when not pressing on the button or when turning the steering wheel, try loosening the tube and moving it down slightly. It may be necessary to grind a small amount off of each of the two horn wire contacts. Do this evenly and a little at a time until the horn honks properly.
