Does this look like it was intended to be keyed, but was welded instead to you guys? I'm replacing the chain and belt, possibly the brake disc, and was going to go ahead and disassemble/clean the rest up and check/replace the bearings as well, not that I've tried very hard at this point, but kind of stuck right here for now. Going to take the other side apart tonight and see if it looks the same. I'm assuming this is the rear axle hub and it's going to need to be removed to replace the brake disc, there's no give or slide in it at all with a gear puller so not sure how to proceed.