I was given a used 1/2" Milwaukee 18v impact wrench. It was well cared for and not abused. My experience is primarily with air tools. I recently did a brake job on my nissan PU and rotated the tires while they were all off. I'm having problems removing sockets from the wrench. It doesn't matter what sockets I use. I've tried impact and non-impact deep and shallow well sockets. Deep well are a little easier because I can get a better grip on them. Shallow ones have become a pain in the butt to remove. In a few cases I had to resort to prying them off. I tried cleaning the hog ring and it's groove but that didn't do much. Do hog rings wear and require periodic replacement? Is this a problem common to cordless impact wrenches (I haven't experienced it with my air impacts)? I've read to not lube the ring. Is this an absolute no no?