how to get grease in a stopped up bushing?

I agree with the others. Always start with removing the fitting and cleaning the passage behind it.

 

you can also take the load off the respective joint too to help remove any pressure.

 

on the fishing boats equipment took a beating from the salt water but heat always freed the old grease up. and yes if those fittings were always greased they wouldnt freeze upo

 

Gearjammer and the others have the right idea. You have to clean out the bore of the pin, get all that old dried up gunk out of there. Spray and soak the inside with a good penetrating oil and try to grease it, then if needed, give it a treat with the torch!

 

I take the weight off the pin, heat the spring eye, connect the air/hyd greaser full on and wail on the spring or shackle with a BFH. Works every time!

 

Boiling atf works great as pentrating oil! Just becarfull!!

 

Told my 13 year old son grease anything that looks like a nipple on a boob. He quit giggling after bout an hour

 

Keep in mind many zerks are made of soft metals, like brass or bronze, and after many years of abuse the head can snap off if you aren't careful with the female grease fitting.

This leads me to caution that you should go over the area around the zerk with a stainless steel brush, some penetrating oil, and a torch just to loosen things up a bit before you bring out a wrench, and break the zerk from the hex collar down.

Learned that the hard way as a kid with my MGB.