C9X--To add to that reply---I have, somewhere in my archives, a procedure from G.M. for tightening the lash in a Vega box. There is a caveat that everyone should be aware of. It goes like this---Many people loosen off the big nut, then tighten the lash screw untill the steering box "binds" a bit when turning the input shaft, then back off the nut a quarter turn and tighten the nut. According to G.M. this is totally wrong. If you back the lash screw off at all before the nut is tightened, then your adjustment will not have any effect!!! The correct way is to loosen the nut, tighten the screw WHILE TURNING THE STEERING BACK AND FORTH A BIT FROM ITS CENTERED POSITION. As soon as ANY resistance is felt, then stop and tighten the nut. DO NOT loosen the lash adjustment screw off before tightening the nut.---Brian