OK I fixed the clunk on my Silverado by changing out the intermediate steering shaft (Rock Auto, 50 bucks....easy) but now I have the same "groan" when making a 90 degree turn that my GFs 03 Tahoe has.

Any ideas?

There is a five inch sleeve that the steering shaft passes through in the firewall. My old shaft was slathered with grease. Is it possible that this new shaft is dry and making the noise? It doesn't seem possible, but I'm up for suggestions.

 

Did you check the PS fluid? If so, I'd suspect the PS pump.

 

Pitman arm CC joint there's so many things
best to Jack up truck and see were play is or wait till it breaks

 

Fluid is fine. The noise emanates from just behind the steering wheel, as in within the confines of the cab, right behind the dash. It doesn't appear at all to be suspension related.

 

Had the same exact problem. Take the bearing out of the back of the column and grease the crap out of it. I did that 2 weeks ago and the clunk is gone!
And don't do that hose clamp around the column tube fix so many forum threads say to do.