If you want a quick fix, raise the hood, loosen the bolt on the intermediate shaft. Work the shaft back and forth about 10 times. Tighten the nut back. Takes less than 2 minutes total. This redistributes the grease. My 07 was rattling. Did this quick fix and it is now silent. Who knows how long it will last, but for a couple of minutes and no money, it is well worth it.
Also, I had a 2001 Suburban with the same issue and I bought the grease kit from GM and it worked too. I sold it after I had put about 15,000 miles on it without any more rattle.