Just how much in the way of tools and spare parts do you carry? I get asked that question quite often, and in reality, I don't carry much. What I do carry is based on what I've needed in the past and where I'm going. I practice what's called "preventive maintenance." Every time I open the hood or air up a tire, I do a quick check of components for their overall condition. If there is any question as to its life expectancy, that component gets changed. I make a practice of washing and lubing my vehicle after every trip. I would much rather note a frame crack, or a bent tie rod, or a worn tie-rod end and replace or repair it in my garage than out on the trail.
We have all seen the big long list of what to carry. About every year one of the magazines covers this subject. I just wonder what kind of a vehicle the authors drive. Surely not a flatfender Jeep! Some of these lists are so long, it would fill a pickup bed, and includes anywhere from a quart of oil to enough for an oil change, coolant, power-steering fluid, and gear lube. Most trail rides are one-day affairs. If your vehicle uses or leaks enough fluid that necessitates carrying these, then should you really be on the trail?
Let's take tools, for example. I don't take a full toolset because I don't really plan to rebuild my engine or other driveline components on the trail. I take a look at just what I would need to, say, tighten header bolts, change a U-joint, replace a V-belt, or replace a U-bolt. This means maybe a couple each of 3/8-, 1/2-, 9/16-, and 3/4-inch wrenches and matching 3/8-inch drive sockets, ratchet, and extension. Add a pair of wire cutters, big and small adjustable wrenches, Vise-Grips and Channel Locks, hammer, punch, and several different screwdrivers.
Hoses? What's wrong with taking a few extra minutes when you're cleaning up your rig and checking things like this? Even if you should blow a hose, it can usually be repaired with a beverage can and duct tape to get you home.
There is a small air compressor from Extreme Outback, (because there is no room for a Power Tank in my flatfender) and an ARB tire-plugging kit, mainly because my spare is usually a lot smaller than the tires I choose to run. When we used to spend weeks traveling in Mexico, there were tire tools, a couple of boots, an innertube, many spare parts, and a lot more handtools.
OK, there are probably a few others that get tossed in as I find a need. But every year, I reevaluate what I have and what I need. Oh, and I don't carry low-cost tools. I save those to loan out of my shop to sons-in-law. What good is a tool that just may round off on a bolt or break when you don't have a backup?
Something that's always with us on western Montana trails is a shovel, a water bucket, and either a large bow saw or a chainsaw. The need for these is pretty self-explanatory.
OK, I carry some parts and repair items, such as an accessory drive belt which doesn't take up much room (which fits both the P/S pump and the alternator), a roll of quality duct tape, epoxy and RTV sealer, some utility wire, a couple of hose clamps, baling twine, and a length of nylon rope. There's two U-joints and a pinion yoke, and a couple of U-bolts, because I've broken them before. An assortment of nuts and bolts is stashed away (not sure why, as I've never used them.) There's also a 20-foot roll of electrical wire, connectors, and fuses.
Because my wife and I often hit the local trails alone, there is a Warn Winch accessory bag with even some extra shackles and chain. This has saved us a night on the trail and a walk-out the next day more than once. For "just in case," there's always a stash of high-energy food, a couple of space blankets, change of socks, jackets, watch caps, and warm gloves. There is a well-stocked first aid kit (even with a suturing kit left over from our Mexico travel days), matches, and fire-starting material. Because the Jeep is painted military OD, there is even a bright orange fleece blanket that could double as a signal flag.
OK, I'm sure that there is some stuff I've missed that's tucked away in a corner some place. The idea here is to think about where you're going and what you may possibly need, what you've needed in the past, and what your level of skill is in making that repair. Don't take any more than you need, but do take what you may need.