on mine someone spun the bushing reaming it. It took a huge torch and a 30 ton shop press to get the pin out. You might want to remove the zerk and see if that's the case on yours. If so the thing will never get greased right. If you follow the link on my sig you can see an example of that. If the goons who'd done the job in the first place had checked it, they could have just drilled a hole in the bushing after reaming and forgotten about it.

\'59 Chevy 1-ton
'72 c-10 (in progress)
The Great Rust(less) Mountain
\'47 Jeep cj2a