Any time something needs fixed on one of my trucks, I give things a good checking over. A lot of time I find something that is wearing out but not gone yet. Especially if I had to tear a bunch of stuff apart to get that far, I’d rather replace it while I’m there rather than have to tear it all apart again. Every time I haven’t done that, I’ve ended up doing it over again within a few months. So I try to be a little proactive on things. If the part isn’t really worn out but just hard to get to, I’ll usually throw the old one on a shelf in my shed or something so I have a serviceable spare if I need it. I also usually stock some common parts like an extra set of brake parts. When I’m busy and a truck I need breaks, I need to be able to fix it quickly and waiting a couple days on parts isn’t always practical.
Stuff like spark plugs and air filters and stuff is basic maintenance stuff. Unless you have one of the infamous Triton 5.4l motors that likes to yeet spark plugs out (Rangers never came with those), spark plugs typically just wear down over a predictable lifespan. Same kind of deal with air filters, eventually they clog up with dust and dirt and stuff. That stuff just gets replaced as needed, but if you wait too long, it just usually results in poor performance and fuel economy, not something major like watching one of your rims and tires pass you on the highway because something important broke.
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