BASIC TRAIL REPAIR GUIDE

Author:
This is just some basic information for when (not if, but when) something actually breaks on the trail. Some of the information is a redundant and shows up in other information here, but the most important thing is simply to be prepared.


Backcountry Repairs

"How to be prepared for a breakdown on the trail"
by Todd Adams
Editor's note: Todd is an expert mechanic and avid 4-wheeler. I got to know him on the Elephant Hill 4WD trail which he leads during Easter Jeep Safari in Moab, Utah.
When going off highway you can never be totally prepared, or take everything you need to handle every breakdown situation. But if you take a few essentials on the trail, you can usually make repairs to get back home or at least back to camp.

If you have done your preventative maintenance right you won’t have to worry about belts or hoses going bad on the trial, but there are plenty of other things that can lead to breakdowns. Some of these are self-induced shock failures that overtax certain components past the breaking point. I will try to list the most common types of breakdowns and how to deal with them. This does not necessarily mean a permanent repair but a repair to get you home. I am going to list these breakdowns in an order that is only relative to my experience and nothing more. Everyone will have their own trail breakdown and repair stories. I have heard quite a few that are ingenious; from wooden pistons to bailing wire stitched up side walls. What you need is on the spot cleverness to deal with some problems, and with others an experienced mechanic. I will assume that you at least have a working knowledge of mechanical repairs.

If you don’t have much experience with repairs or even if you do, a smart item to carry with you is the service manual for your vehicle. A good mechanic always reads through the repair procedures before he starts a job he is not familiar with. Another thing that a service manual will tell you is if there are any special tools required. If there are, then these tools should be part of your tool kit. You would not need a special tool for a transmission or engine rebuild on the trail but if you need something special to pull a front half shaft, you had better have it with you. This isn’t to say that you need to fill the back of your vehicle with tools. I get by with just small tool sets and a few special tools that apply to the particular vehicle I am driving. For example, if you have a full size Ford or Chevy, you should carry an axle or spindle nut socket

There are lots of things that can cause mechanical failures on the trail. If you drive your vehicle regularly these things should show up when and where it is easier to deal with them than in the outback. If you have a "trail only" vehicle you should drive it on the road once in a while just to see if there are any problems. It is more common to see problems with trailered vehicles than with daily drivers.

Every situation is different so it would be impossible to list every possible cause and repair procedure for a breakdown. Here are some of the most common types, starting with tires.

Getting a flat tire is by far the most common type of breakdown. Always carry a good full-sized spare tire. You might want to pack a plug kit, but most of the tire problems I have seen are either not reparable, or simply a lost bead. One of the first essential items everyone that goes off highway needs to get is a good air compressor. Airing down to gain better traction is only outweighed by the increased ride quality. This will increase the odds of a lost tire bead however. Make sure your jack is in good working order. If you carry a High Lift Jack on the outside of your vehicle, check and oil it often. Another handy item for tire work is a nylon winch-type hold down strap. These can be put around the center of the tread and tightened to re-seat the bead. Never use starting fluid to re-seat the bead. This has lead to fatalities. It is a good idea to stand away from the tire when airing up. A sidewall can fail, causing what is known as a ‘zipper effect’. I prefer to carry a star wrench. It is easier to use to get lug nuts off and on than the lug wrench supplied with the vehicle.

The next most common problems, and some would argue the most common, are engine stalling problems. Other than a major internal mechanical failure, these can be divided into two types: fuel or electrical. Let’s start with fuel problems. Off camber situations are the norm when going off pavement. With a carbureted engine that was designed to operate mostly on the near level, off camber can cause flooding, or over-fueling, of the engine. This condition can also create a dangerous situation. Gas running out over the engine can lead to a fire under the hood. There is an easy fix for this; an adjustable fuel pressure regulator mounted at the inlet to the carburetor, set to 2 or 3 psi when off highway.

You can also lose fuel flow due to fuel pump failure or vapor lock. Some vehicles are more prone to vapor lock than others. Vapor lock is caused when the gasoline boils in the fuel line. This condition becomes more common with an increase of altitude. The temporary cure is to wait while things cool down. The permanent cure is to install an electrical fuel pump as close to the fuel tank as possible. If you have fuel pump problems, you might consider packing a spare electric fuel pump with your tool kit. Fuel injected engines are much more reliable However they need professional help to repair. Fuel injection also doesn’t care what angle you put it on.

The other thing that will cause an engine to stall is loss of the electrical system that fires the spark plugs. The older the vehicle, the easier the electrical system is to check out. The newer it is the more reliable it is. Other than getting wet, a basic understanding of the electrical system is needed for a proper diagnosis. A can of WD-40 should be in your tool kit, especially if stream fording is anticipated. If you stall after getting the outside of the engine wet, you will need to get rid of the moisture inside and outside the distributor cap, coil and the sparkplug wires. Spraying the WD-40 in these areas will dissipate the water. The use of silicone dielectric or tune up grease on the inside of the ends of the sparkplug wires and coil wire will effectively seal out moisture permanently. The only thing left to completely seal the secondary electrical system would be to seal the distributor cap.

The way to tell, when the engine stalls, if it is a fuel or an electrical problem is to pull a sparkplug wire off and turn the engine over to see if you have spark. You need to be careful when doing this as there are around 30,000 volts that can give you quite a shock. I will usually pull the wire off of a sparkplug and put a screwdriver into the end and lay it on the intake manifold so there is about 1/4" gap between the screwdriver and manifold. Have someone turn the engine over and watch for the spark. If you don’t have a good spark jump the gap then you can assume you have an electrical problem. If you get a good spark then chances are you need to look at the fuel system.

Next comes breakage due to over-taxing your vehicle. The weakest link in the drive train seems to be the U-joints. If you break a U-joint there is a good probability that you will damage the yoke as well. This usually is not a trail side repair. Just remember that you are driving a four-wheel drive vehicle and you can most often get home with either the front or rear drive disconnected. You will need to remove the drive shaft with the broken U-joint so that further damage is not done, then drive out in two wheel drive. If this is a front axle steering knuckle U-joint, the half shaft will need to be removed and a rag stuffed into the end of the open axle housing. If the drive shaft that needs to be removed has a slip yoke that splines into the back of the transmission, you will have to figure a way to keep the fluid in and the dirt out while getting where you can make permanent repairs.

Broken axles are also common. The type of vehicle you drive will determine if you need a ride to town to buy a new axle and replace it where you broke it, or simply remove it and drive off in two wheel drive. Full floating axles are the easiest to deal with. Simply unbolt both axles, push out the broken end, re-install the axles and drive home in two wheel drive. On the other hand, if the wheel is retained by a C-clip inside of the differential housing, then you will have to go to town for a new axle. There are many variations of axle retention so there is no way I could list all possible trail side repairs.

Engine fan contact with the radiator is another situation that I have seen on the trail. There are two ways in which this can happen. The first is during deep water crossings. The fan can be pulled into the radiator core when the fan blades are bent forward by un-compressible water. The other way is during a high torque or frame flexing maneuver like trying to make " Zukie Hill ". This type of repair will require you to pull the radiator. You will need to pull out, pinch off and solder the leaking tubes. As part of your kit you might consider a propane torch and acid core solder. This procedure does require a firsthand knowledge of soldering. Modified vehicles are more at risk, due to body lifts and engine swaps, but I have seen this happen to new stock vehicles where the fan is close to the radiator.

Brake failure is something you want to repair before you go any further. One thing you never want to do is drive off pavement without a good parking brake. The usual reason for a brake failure is a leak. With modified vehicles it is usually due to brake lines having a hole rubbed into them from an overlooked body panel or too tightly stretched flex line. Older vehicles had only one brake system so if you developed a leak you would lose all the brakes. Newer vehicles have a front and rear brake system, so if you lose one system you will still have partial brakes. One way to deal with this on the trail is to pinch the leak off tightly with a pair of vise grip pliers, add brake fluid and bleed the brakes. Keep in mind that this will cause the vehicle to pull to one side. If you have to do this with a front brake it can almost pull the steering wheel out of your hands on a hard brake application. This would be only a very temporary repair but it would be better than no brakes at all. You would be better off going to town, buying a new brake line and repairing the brakes properly before going on.

There are certain precautions you should take before heading to the outback. Give some serious thought about what you would do if a major breakdown occurred. Could you deal with a major breakdown on a little used trail with no-one else around? This could lead to a life threatening situation you should have avoided in the first place. You should never go it alone on a remote, seldom used trail. This is one of the reasons 4X4 clubs are popular. Even if you don’t chose to join a club, trail ride events are scheduled most times of the year and everywhere in the country. There is security here, with all kinds of help if you have any problems. It is also the best way to gain off highway experience. If you do chose to go off alone, give yourself an out. Don’t go further than you can walk out and find help or shelter before dark. Carry food and water enough in case you have to spend the night with a broken down vehicle. Be prepared for an accident with first aid supplies and training on how to deal with injuries. Always let someone know where you are going and when you will be back.

More information on what people carry in their rigs can be found here:

http://www.frontrange4x4.com/forums/...your-rig/page2