I'm trying to get my 99 Jimmy in shape. I'm a little rusty at repairs, cause the car hasn't really needed much since it was new. Of course now it'* not so new. I recently replaced the intake manifold gaskets and all the brake pads and rotors. Now the only thing left as far as I know, is a bit of a wobble, mostly at highway speeds. Most everything seems pretty tight (ball joints, ect....), cause i've kept them all greased regularly. About all i can see is this assembly in this video I made. It looks like the assembly is wobbling up and down, maybe more than it should. It looks like a 2-piece assembly. Should I replace both parts? What are the parts named? Please look at this utube video that shows the wobble, and advise ......( actually, now that i look at the video myself, I think maybe the assembly is made to move that way, to compensate for any up and down movement of that big long arm that it attaches to, and I think that big long arm connects to the steering box). Could my steering box be worn- I don't think so, cause i've kept the steering fluid level correct, and occasionally, I've siphoned the steering fluid out of the resevoir, and refilled with GM brand steering fluid. Is there any adjustment to tighten the steering box? Or do they make some kind of aftermarket steering damper add-on for a deal like this? I'm also looking at the possibility of a worn hub bearing, drivers side. There seems to be quite a bit of play in the drivers side front hub. But no grinding or humming noise coming from it, just wobble...............Sure, I'd like to buy a new GMC Terrain, but that ain't gonna happen at this point. Thanks, Mike Here'* the video........ Front end wobble - YouTube

The part that mounts to the frame is called the "idler arm". And yes, it does have quite a bit of slop in it. Get her swapped out. But, be prepared to buy more parts, cause once you replace that one, you might notice other parts with slop in it that you didn't see before.