....2009 Silverado 3500HD, DRW, CC, 4x4. 32609 miles, it's not a daily driver and sees mostly camper hauling or trailer towing duties. The idler arm and pitman arm are toast. /rant off.
There are 9 lube points on the 2011 and later trucks and 11 on the earlier ones and the recommendation is to lube them every 3,000 miles. They are not "lifetime" lubricated like the 1/2 ton pickups and SUV's which also wear out.
When oil changes were done every 3,000 miles the chassis lube was done at the same time. Now with the use of synthetic oil the service intervals are much longer and the front end parts suffer from the neglect.