I put on an aftermarket shift knob a few years ago and ordered a new one as well as a new shift boot. When I went to replace the knob, I found that the current one is stuck. I have gotten almost rotation on it, but it will not go more than that. The old one came with a nut that I put on with the knob and after reading some other people’s problems on the forum, I’m realizing that it might be a locking nut that is preventing the knob from screwing off. I’m not sure if I somehow cross threaded both things, or if I just need to go to the gym. I have put lubricant on to try to loosen it up… no cigar. Any suggestions are helpful. I will add a photo below.