I got frustrated and haven't greased them nearly enough. Today, I removed the pins, cleaned them, drilled an 11/32" hole just down to the hex. I was able to partially thread the hole with a 1/8" tapered pipe tap (standard) I had to grind the end of the tap off a little to get as many threads in as I could. Now I can screw a standard grease fitting enough to hold it. I put a grease gun on and forced some grease in. Of course the fitting gets removed and the cover replaced. Next time, I'll pick a bit of the grubby grease in the hole out and I'll be able to pump some fresh grease in.