The following is an animation of steering column disassembly.
Some explanatory illustrations: Click any image to start slide show, (a pause icon is in upper right corner)
If the peg is not sufficiently engaged into the cam there will be excessive play in the steering. If it is engaged to much the steering will at first be very stiff and then wear loose and become junk. What we commonly call a worm is really a cam in that the slot is not uniform. The slot is made so that it is narrower in the middle where the peg rides when travelling straight and wider in either direction from the middle. The idea being that when turning the force will be on one side or the other of the slot so additonal clearance is OK.
Adjusting the Steering Assembly
I recall seeing real instructions for steering adjustment in some manual somewhere. Can’t recall where. It was a proceedure I was not able to do. Maybe it was that I didn’t have the right tools or maybe that I work alone and the correct proceedure benefitted from a second set of hands. So Caveat Emptor, the following is how I adjust the steering, not the preferred way. 1. With the sector (pink in the above illustrations) out of the housing mark the peg then use a punch to knock it out of the secctor arm. Rotate it 90o and press back in. 2. with the column assembled, centered and with the adjusting screw on the top cover loose: push-pull, in out, on the steering wheel hub. There should be no in-out movement (end float). If any play is felt then one or more shims must be removed. 3. Use a Broad screwdriver to tighten the adjusting screw until it is “slightly” snug on the worm/cam. NOTE: many cams have been ruined by overtighening! 4. Put everything associated with the steering back and test drive. If there is excessive play when driving in a straight line return and tighten the adjusting screw a 1/4 turn. Repeat until there is minimum play when traveling straight then test at highway speeds.
Steering is of course a SAFTEY OF LIFE function. Work carefully and if at all possible have all work done by a knowlegeable professional.