While this adjustment can be done with the box mounted in the car, ideally it should be done out of the car and mounted securely on your workbench. It will also be a lot easier. Start by loosening the locknut on the sector shaft and back the sector shaft adjuster off about 1/2 a turn. This will help prevent friction from the sector shaft/worm gear interface from affecting the worm gear adjustment which we will do next. Now loosen the large lock nut at the back of the steering gear. You may need a pipe wrench for this as it's a pretty large nut. Once you've loosened the lock nut turn the worm gear by hand using the splined end that goes into the steering shaft coupler. If it has any end play [ pull & push it back and forth ] turn the large adjuster that screws into the body of the steering gear clockwise. You may wish to loosen it first so you can tell what a little end play feels like. In any case what we want is zero end play plus a SLIGHT amount of preload. You can use a drift punch in one of the holes in the adjuster to tighten or loosen it. Now tighten the large lock nut. Next we need to find the center [ high point ] of travel. Turn the worm gear by hand [ either direction is fine ] to the limit of travel. Now go the opposite direction and count how many turns it takes to the opposite stop. A standard gear will be close to SIX turns [ ugh ]. Once you've done this go back exactly 1/2 the distance. This is the center point. Now tighten the sector shaft until there is no longer any free play. It would be best if you can hold the worm gear securely with one hand and use the pitman arm on the sector shaft with the other hand to check for free play. Again what we want is zero free play with just a touch of preload. Now tighten the sector shaft lock nut and you're good to go. This may sound complicated, but it's actually fairly simple. Good luck.