I posted about a problem with the intermediate steering shaft on silverados here some time ago.

I contacted GM folks, got the story that the noise/vibration I felt in my 2002 Z71's steering was a known problem, not a safety hazard and would not be the subject of a recall.

Today, however, after discussion with my local Chev. dealer, the intermediate steering shaft ( that portion of the mechanism which is observable under the hood and under the dash) has been replaced under a "goodwill" program, free of charge.

To recap, I felt the vibration and took the truck to the dealer (under warranty) and they installed a 'lube kit' at 9600 miles. At 15K miles, the problem was back.
Spoke to the dealer and GM folks. They knew that the problem existed, but no recall, no program.

Now there is a program bulletin and a fix?, anyway they replaced the shaft.

Thanks to GM, may yours be fixable also.