Because the lash adjuster screw has no where to hold onto the steering gear. The steering gear would push all the way in until it hits the side of the gear box and do nothing else.
Heres what Im talking about. According to my manuals there should be a lip on the end of the steering gear.
Does that make sense now? My intent would be to add a thrust washer or machine bushing on the other side of the shaft so that it would move the tooth contact into a full position between the steering gear and the worm gear block, otherwise there would be about 1/3 less tooth contact and the steering gear would rub against the inside of the gear box. All the lash adjuster does now is apply end pressure. It cannot be used to move the steering gear back and forth.
