The two bushings are used on the pitman shaft, so the play can only be seen where the pitman shaft comes out of the box where the pitman arm attaches. The proper bushing fit will prevent any side to side or up and down movement. I would try moving the pitman shaft and look for movement of the pitman shaft. You should make sure you go through the steering box adjustment process as outlined in the manual, before checking for excessive play in your steering box. Are you having issues with sloppy steering with your truck?
