I realize this thread is old, but it's the only related one I can find.
My checks (especially driver) are worn out too. Very annoying, as the door won't even stay open on flat ground. Before spending $140, I figured I'd try a free fix. I put two part epoxy on the two "bumps" of the check, to try and build it back up. Crossing my fingers that it will work, but I have my doubts. I wasn't about to install it back in last night and risk epoxying my door shut
so I'll mess with it tonight. I'll report back as to whether it seemed to work or not. I can't be the only one with this issue, given the age of these trucks now.