I feel like I knew what this thing was right up until I had one. Two tool id site had no idea, and one said it’s a ball joint separator, but I can’t find any that look like this, and I swear I’ve seen them in stores, but can’t remember where.
Maybe a type of bearing press?
That makes sense. It didn’t come with the other part, but there’s a bunch at a thrift store nearby, which must have been where I’ve seen it before.