98 Tahoe Steering Wheel vibration

[nygacr95]

Okay, this one has me puzzled....

I just got a set of tires put on my 98 Tahoe, (4wd, 115K miles) and I noticed a wobble/vibration in the steering wheel around 35 mph, that seemed to go away around 45 mph. It felt like a bent rim, and i figured it was one that was in the back I did not know about or something, So I swapped the front tires to the rear. no change....

I looked at inner and outer tie rod ends, pitman and idler, and everything seems in sorts. I replaced the inner and outer tie rods a good year ago, probably 15-20K miles previous. Recently there was something that knocked the toe out a bit, and I got everything parallel, but I suspect the alignment off a slight bit, which I want to get aligned, but want to fix anything else before I do so...

From what I read on the forum, so far, this sounds like a possible front hub, but I am not sure. I don't know why I want to think ball joints, but they seem to be on my list. From the discussion on rotating items causing vibration, that is why I am thinking hubs...

Here is more detail to what I get.

The vibration starts after the Tahoe rolls over something in the road, a bump, highway separation, sewer cover, etc.... it needs to be going around 35 mph, at least, and the steering wheel starts moving back and forth, maybe a 16th of a turn, a bit less.

The steering wheel does not center, but when you put it in perfect center, if the road is level, it will go down the road almost perfect. seems I notice the vibration if the road is more banked, and the wheel is slightly to the right, and the above conditions are present.

I guess I am looking for any advice as to how to diagnose whether I got a hub going bad, and what I can do to determine which one it is. I don't mind changing one or both, but would prefer to only change one, if only one is bad.

So if anyone has any ideas, any help would be appreciated.

Thanks!

[GMMerlin]

What you are describing is a shimmy. Typically this is caused by a worn steering component.
I would venture to say that the pitman arm is what I would inspect closely.
Also the fact that the toe has been knocked out would indicate damage with the steering system.
Good physical inspection is needed

[Genopsyde]

did you ever pinpoint the cause of this? I'm having a similar issue with my 98 Tahoe.