A few weeks ago I posed a question about my 97 1500 WT's steering to this news group and got a lot of good feedback. The feedback sent me on a quest to fix a truck that drove like a Model T. The truck steered light and wandered all over the road, especially when applying the brakes. I checked all the suggestions I was given and all checked out OK.
Being stumped, I took it for another opinion to a front end shop and had it checked again. They checked the alignment and drove it and told me they found nothing and thought it drove pretty good. I have had three different shops drive the truck and each thought it drove OK. I knew better, I guess they're accustomed to driving off road monster trucks or something.
So after eliminating all the front end components and the steer shaft, I was left with one conclusion, it could only be the steering gear box. After a little research, I learn of the adjustment on top of the steering gear box that takes the free play out. A five minute job. Just loosen the retaining nut and tighten the allen set screw about a 1/4 of turn. Then recheck the free play in the steering until you have only about a inch of free play between the steering wheel when the tires begin to turn. If you have more than that repeat the process, careful not to over tighten. Now the truck drives so good, I may keep it a while. Relayed this info to a friend who's wife drives 96 Suburban, with a similar complaint. He made the fix and was amazed as I at the difference of night and day.
Anyway I threw this out there because it appears that this is common occurrence on GM truck pre 1999, in hopes it will help someone else and save them the time and aggravation I went through.
RC