This post is literally my life five days ago — my truck lost a wheel two blocks from home. Snapped almost every stud. I managed to get it back on with the two that were still holding and crawled home. Suspension was worn out. Fixed it myself with an oxyacetylene torch and a grinder because waiting on a shop wasn't an option — that would've cost me more time than the repair itself.
My backup was my personal Ram 1500. Threw the trailer on it and kept running. Probably pushed it a little past what the manufacturer recommends, but the schedule didn't stop.
The honest answer to your question: as a solo operator you can't fully protect yourself from this. What you can do is have a backup vehicle capable of doing the job, know how to fix things yourself, and have the kind of schedule flexibility to absorb a half day without it cascading into a week of chaos.
What I'm taking from it — I'm looking at replacing the older trucks with something in better condition. Time spent fixing equipment is time not making money. At some point the "cheap" vehicle costs more than the reliable one.
