Most of us have figured out that if we’re lazy with 4x4 maintenance, we pay for it in the long run, and more than likely at the least opportune time. Checking the engine oil and coolant level regularly is pretty common for a shade-tree mechanic, but, when was the last time you took a peek under your 4x4 to see that everything was OK? You can save yourself and your trail buddies a lot of headaches by simply giving your vehicle a once over before you head out on an excursion and then again at the end of the trail, before your drive home. It only takes a few minutes to trail prep by looking over the key spots that could cause you trouble. Fluid leaks are the most obvious and are the first things we look for. There are many different components that carry various types of fluids in your 4x4, so it helps to learn what each fluid looks and smells like. Knowing what the fluid is can also give you a better idea of where to take a closer look, especially if the whole underside of your 4x4 is slathered in an oil slick. Check for potential leaks everywhere, including the radiator, coolant hoses, water pump, battery, engine, transmission, transfer case, axles, power steering, shocks, steering stabilizer, CV joints and so on. Look for a wet spot or areas that have collected an unusual amount of dust; in most cases, a few drips won’t stop you in your tracks, but a real gusher of a leak could quickly kill an engine or other drivetrain component. Assess how bad the leak is, then check and add fluid if it’s at all questionably low. Leaky shocks and steering stabilizers can usually get you home safe, provided they are not bent, crushed or too damaged to cycle properly, however, they should be replaced or rebuilt as soon as possible. While making your rounds, inspect for obvious damage. This could include a candy-striped or dented driveshaft, bent tie rods, broken wheel studs or a cracked frame; broken shock mounts, motor mounts and transmission mounts are also common on well-used 4x4s. Sometimes a skid plate can get crushed and pushed into a vital component like a driveshaft or oil pan, so be sure to address or repair anything that looks suspect. Loose and missing hardware is also a common find on a 4x4 that sees regular trail use. If you learn to understand how the components under your 4x4 work, you’ll be more able to predict what hardware is under the most strain. Suspension and steering components such as shocks, track bars, steering boxes, tie rods, draglinks, control arms, U-bolts and so on are some of the most common items to have loosened hardware. Meticulous individuals like to use a paint pen to mark the nuts and bolts, that way you can quickly see if something is loose or out of place. Under the hood you can do the standard fluid inspections and you might want to take a look at the air filter. If you’ve been on particularly dusty trails, you should at least remove the air filter and knock out the majority of the dirt. If dusty or swampy trails are a common occurrence, it might not be a bad idea to simply carry a spare air filter that you can swap in for the drive home. This will help increase fuel mileage and keep dirt out of your engine. We have seen a lot of batteries jump out of their mounts, so make sure yours is firmly in place and not rubbing on a pulley or intermittently shorting out on the hood when it bounces around. Your tires receive all kinds of abuse both on- and off-road and need to be looked over regularly. Inspect the sidewalls, tread area and valve stems for damage or dry rot that could cause a blowout at speed on the highway. Remove nails, screws and other sharp objects that have embedded themselves in your rolling stock. Spray soapy water on the suspect areas and look for bubbling to help locate escaping air, then properly repair any leaks; tire plugs in the sidewall are fine for the trail, but are a no-no for the road, so replace any offending tires.
What To Inspect on Your 4x4:
Inspect the cooling hoses closely. Small leaks can sometimes be remedied by simply tightening a hose clamp. If you find bulges and squishy spots in the hoses, they need to be replaced before the next outing.Twist and check the drive side of the accessory belts. If they are cracked like this, they are due for replacement. It’s always a good idea to carry spare belts and hoses when traveling off-road a long ways from the nearest parts store.Some wet cell batteries have a tendency to leak acid inside the engine compartment when bounced around - this destroys the paint and other finishes. For regular off-road use you should consider upgrading to an AGM battery that won’t leak acid, even if flipped upside down. Clean the connections if they are corroded and make sure the mounts are snug so it doesn’t hop out of the tray.One dusty trail, a rough flog in the dunes or a submerging in mud can clog up an air filter enough to significantly decrease fuel economy. Knock as much dirt as possible off of the filter before heading home at the end of the weekend.Split or torn CV boots on half-shafts should be replaced right away because the CV joints won’t survive long once the grease escapes and contaminants get in.The leak from this torn rack and pinion steering boot is easy to spot. There generally should not be any oily surfaces under your 4x4 - if there are, you need to inspect them and find where the leak is coming from so you can assess how bad it is, and if it needs to be fixed before hitting the road.The output shaft and pinion seals are notorious leakers. They have to survive in a really contaminated environment, which can take its toll. If you notice oil drips under your 4x4, these are good places to start your search to find the source.Factory rubber motor and transmission mounts get old and can fail, and bouncing around off-road and ultra-low gearing puts additional strain on them. If they look broken or have dry rot, they should be replaced.You can either use a paint pen to mark your suspension and steering hardware, or you can keep an eye out for loose bolts by looking for disturbed dirt and grime around the bolt heads. If the bolt looks like it’s been spinning in the grime, then it’s probably loose. This bolt is still firmly seated as evidenced by the dried mud around it.Engine, transmission, transfer case and axle fluids that look like a milkshake have been contaminated with water. You’ll need to fix any leaking seals, extend the breather lines or quit driving your 4x4 like it's a submarine. Change any contaminated fluids right away.
