steering very unstable gets worse the higher the speed. 2003 s10 extreme.

We just got a 2003 chevy s10 extreme 2wd w/4.3 for a new shop truck. Guy who sold it put all new balljoints, tierods, etc in the front end. When we drove the truck back to the shop on the highway it was scary, trying to hold the speed limit was hard because the steering wheel was jumping all over like memory steer on steroids. I put it on the alignment machine, it was toed in about a degree total and was cambered in about 1.5 degrees on each side, Caster was even side to side, and it didn't really pull. This has the sliding upper control arms that use shims for camber/caster adjustment. There were already a lot of shims in each side, no room left to adjust the camber out more. I set the toe and took it for another drive, all I can say is it got a little better, but still had to hold on with both hands to try and keep the steering wheel straight. Boss had me order a new reman steering box to try, won't be in till next week. Has anyone experienced any thing like this at all that shed some light on this problem?

I'm still waiting on the new box, I've had time to look at things a bit more. Center bolts on the leaf springs are intact, so the rear diff wasn't dancing around. Found the rag joint steering coupler to be in a bad shape, but steering play isn't the issue here. When I lifted the front end and pushed the wheels side to side a considerable binding was felt left and right of center. So things are kind of leaning toward a binding issue causing extreme memory steer. I was underneath while someone else moved the wheels side to side, there is a bit of binding in the idler arm, as it looks like it slants up slightly when its turned. I did read somewhere that defective idler arms cause jerky steering in the s10s. But also felt slight shuddering coming down the shaft out of the steering box when it hit those hard spots near center. Undid the outer tierods from the knuckles so see if maybe one of the new balljoints was a bit too tight, they didn't really seem to be over tight, no abnormal effort to turn the knuckle back and forth on the balljoints. So hopefully this new steering box, rag joint replacement and an idler arm will make this thing drive semi normal. But now the boss wants to put 19inch wheels on it, and they hit the sway bar and the lower control arm bad front and back when you turn, the rims will be ruined in no time. And to make that issue worse since it is cambered in a bit, and I am unable to add any more shims, the camber is even worse with the 19s than with the stock 15 inch.

Perhaps someone attempted to tighten the steering box lash by over-adjusting the sector shaft preload and not adjusting the gear mesh first.

Perhaps someone attempted to tighten the steering box lash by over-adjusting the sector shaft preload and not adjusting the gear mesh first.

I'm leaning toward that or just a worn out box. I got the new one today, and got it bolted into the truck, but nothing is hooked up yet. With the linkage unhooked from the pitman arm everything goes side to side good, but the old box was bound up I couldn't get it to turn on the bench without significant force, whereas the new box I was able to turn it with a bit of effort by hand but it moved smoothly. Hopefully tomorrow I get everything all done, and can road test it to see if its driveable now. Also have a new ragjoint coupler for the steering shaft, boss won't go for any of the upgrades.

I replaced the ragjoint coupler, and put the steering shaft back in, put everything back together and bled the steering system. Went for a drive down the highway, I'm going to say its 95% better, not perfect but I am for sure saying that old box was junk.