After stopping to see the eclipse last week, we backed out of a Shell station in SC and as I went to move from R to D, the shifter flopped around and locked in P but the indicator showed R. I backed up around other vehicles and cut it off but it would not restart.
The AAA eventually showed up and diagnosed a broken shifter bushing and got us going on our way to Savannah.
After putting the cable end back on the shifter a couple of times I got smart and wrapped a rubber band around the assembly. This held for the next 5 days. I picked up a new shifter cable at GM in Savannah and while looking at U tube, found out that the bushing was available as Dorman # 14055, everywhere but GM.
Easy fix, took longer to buy the part (thanks O Reilley, your cust service is horrible) than it did to fit it. So now I should be good for another 99K miles

 

I have 100k on my '08. What year is yours and I'm guessing is different for the 4 speed vs 6?

 

There was a point in time where everyone's bushings were going bad and most started carrying a spare in their glove box lol.