Denali Steering Issue Help Please

[NorCal Nali]

So my Denali has been making a very strange noise/feeling/vibration intermittently. Here are the symptoms:

-When turned right or left 100% of the way, steering wheel fully turned, it makes a rubbing noise combined with a feeling as if the front tires are skipping across the pavement. This occurs when making U-Turns, or tight slow turns in general.

-After driving for a long period of time straight on the highway, getting off the freeway and making turns (into a gas station, etc.) it makes the same loud rubbing noise combined with the front tire skipping feeling. It then proceeds to go away once I straighten the wheel out.

-Severe bump steer (when going over bumps like intersections or rough pavement with bumps the steering gets really loose and almost feel all over the place

In order to try and solve this problem I have had the idler arm, pitman arm, as well as the tie rod, and end links replaced. This has yet to solve anything and I'm very frustrated! Les Schwab has told me after the 2nd visit that they can't determine exactly what it is. They suggested this last visit that A.) I need to flush my differentials and replace the fluids and ad some type of lube additive so that the clutch in my AWD differentials shifts smoother. AND B.) replace the squealing pully on my supercharger setup because that could be causing the serpentine belt to go slower therefore making the power steering work less.

I am open to any input and appreciate the suggestions. PLEASE help me solve this problem!! Thank you!!

The Denali has 96,000 miles if that helps.

 

[bankswood]

Have you replaced the intermediate steering shaft

 

[NorCal Nali]

Have you replaced the intermediate steering shaft

No I actually have not

 

[bankswood]

Its an easy DIY replacement. Before you replace you can test yours by "exercising" it. Search the forum for instructions on replacing it. Before replacing just remove the bolts on the end of the shaft in the engine bay and pull the inner shaft out as far as you can then push it back in. Bolt it back and test drive. If you can tell a definite improvement then you should replace it.

 

[dthomas2003]

When turned right or left 100% of the way, steering wheel fully turned, it makes a rubbing noise combined with a feeling as if the front tires are skipping across the pavement. This occurs when making U-Turns, or tight slow turns in general.

-After driving for a long period of time straight on the highway, getting off the freeway and making turns (into a gas station, etc.) it makes the same loud rubbing noise combined with the front tire skipping feeling. It then proceeds to go away once I straighten the wheel out.[QUOTE]

My Denali is doing the same thing. If I drive 30 miles or over then turn the wheels it makes that clunking and tire skipping noise. It's got to be heat related. Iv'e read and checked TSB#06-08-61-003 Body mount Insulator. Iv'e checked the torsion bars. Iv'e installed both CV axles. Iv'e changed front diff fluid. Iv'e checked the I-Shaft. I'm looking for a AWD or electrical issue I guess. I hope someone has a answer. I hope to resolve this before it does some damage.