1939-1948 Passenger Pitman Arm Bushings
One of the most common steering problems in Chevrolet passenger cars from 1939-1948 is failed pitman arm bushings. The symptom of this problem is a steering wheel that has too much play and must be turned back and forth constantly to keep the car running straight. It seems to point to a steering box issue. However, the real problem is most likely that these rubber and steel bushings have become soft and mushy and are allowing the steering to operate as if the steering box is out of adjustment.
A simple test for the problem is to have someone turn the steering wheel back and forth until resistance is met. While this is done, look at the joint where the pitman arm and tie rod arms meet. This joint should move together, forward and back – no sideways movement. If there is movement between these two pieces, it will indicate failure of these bushings. Replacement of these bushings will make a huge difference in the steering control of the car.
In 1939, there were two versions of the pitman arm that were used. The early version has two large bushings mounted on one stud. This type of bushing is not reproduced, so custom-made urethane bushings will be required to repair the early version.
The second version was used in later 1939 production and all the way through the 1948 models. These bushings were mounted on two studs and contained four bushings – two upper and two lower – which were identical. These bushings should be replaced in sets of 4 pieces.
Begin by removing the two nuts that hold the assembly together. It will be necessary to remove the tie rod ends attached to the bracket at the front of this assembly. A "pickle fork" or similar wedge tool will be required to separate the tie rod ends from this bracket.
With the tie rod ends removed, separate the two pieces of the pitman arm assembly. Clean the studs and brackets of the old mushy rubber and be sure to get the steel bushing cores as well. The new bushings have a steel core with a tapered side and a flat side. Slide the two upper bushings onto the studs, flat side first. Slide the studs with upper bushings through the lower arm. Install the two bottom bushings, flat side down. Reinstall the bottom plate of the pitman arm assembly, tighten the nuts and install new cotter pins.
New pitman arm bushings will make a dramatic difference in steering capabilities in cars that had bad bushings. If there is still a lot of play in the steering after replacing these bushings, check the steering box for wear.