While removing the old spindle housings (there’s two on this mower), four of the six bolts broke. Not surprising considering the housings are cast aluminum and have spent almost twenty years under a mower. More than half of that time they mowed a yard with a lot of Oak and Pine trees. Having been in such a highly acidic environment, all aluminum parts under the mower are heavily etched. This housing also lost one of the mounting tabs completely. All three of the bolts in the housing broke. Welding the tab back heated the bolt enough to loosen it. Welding nuts to each of the bolts loosened them and three backed out completely. I think this one was broken off below the top of the hole and I had to build it up before I could get a nut on it. I suspect that while building it up, I may have melted the aluminum a little and damaged the thread. While I could move the bolt, it would only move about an eighth of a turn and bind up. After breaking three nuts off, I gave up on that method and just cut the side off the casting and built it back with weld. I’m well aware that this isn’t worth this much work, but this is the dirtiest cast aluminum I’ve ever welded on so it was good practice.