I never took the freehub or the cog off at all. I did degrease the whole thing though. It was really cleaned out. I could really lube it up a lot more as I most likely didn't put enough on, but when I pedal slowly and even sometimes just normally it like the rear derailleur jumps all over the place and the whole thing just becomes a mess. If I shift just one cog up, the chain becomes tight again and works pretty normally. It's only that one combo, every other combo works, even the big/big cross chaining works. It's very confusing, I could possibly take a video if you want me to.