I drove charter buses back in the 90s. An elderly neighbor told me he had wanted to be a Greyhound driver when he was a young man, so he went to apply for the job. He said he was told he would have to start out washing buses, and at some point he could begin training as a mechanic. After a few years as a mechanic, he could learn to be a driver. This way the drivers could usually take care of whatever needed to be done on the road, would be less likely to abuse equipment, and so on. He decided to try something else. I'm pretty sure he said that was in the late 30s.

Even when I was driving charters and tours (not for Greyhound), we were expected to get the job done by whatever means we could. Having been an auto mechanic myself, I carried a basic set of tools which came in handy many times. On tours, we carried an impressive selection of cleaning supplies. Mops, squeegees, 100 feet of garden hose. More than once I took five gallon buckets of warm water from the bathtub in my room down the elevator and out behind the hotel to scrub the bugs off the front of my bus.