This string reminded me that I had not greased the zerks on top of the Dexter axle castings. I proceeded to do so and was on the last side, the last zerk and I reached for it to put grease gun on, and the zerk came off in my hand!! It didn't appear to be broken off. I attempted to rethread it back on but that was extremely difficult and couldn't get it to take. I then removed one front wheel to get better access and decided to put in a new zerk. There was no evidence that the original zerk had broken but if it had the lack of access there would have made extraction very difficult. Also there is insufficient clearance with the trailer to run a die to reestablish the threads at least with the tools that I have. I shudder to think but it seems you would have to lift the trailer off the axle to get sufficient clearance to rethread those zerk holes. Furthermore, the original zerk had very short threads, perhaps because the Dexter casting is not very thick. To make a longer story, shorter, I did manage to get a new zerk in tight. I doubt the threads are well established but the new zerk seems threaded in at this point. That zerk will get TLC from this point on because the alternatives for repair look pretty ugly. Also after three months or 3000 miles I find the zerks will take only minor amounts of grease before it oozes out of the joints.