1. Check the Basics
Check all your fluids -coolant, oil, windshield washer fluid, power steering fluid, brake and clutch fluid, ATF, differentials, etc. Make sure there are no leaks, everything is at the proper level, and carry extra fluids just in case. Also check the air filter and the air filter box for debris. Also, if you are aware of any mechanical or electrical problems with your 4x4, repair them before hand.
2. Check the Tyres
Check the condition of your tyres, including the spare. Be sure they are all inflated to the proper highway speed pressures. Take note of your tread and think about the terrain you will be travelling on. Are you ready for that deep mud hole with that tread?
3. Ball Joints
Check all your ball joints, tie rods ends and wheel bearings by jacking up and securing the front of your 4x4. Grab the tyre at the top and bottom, and check for any excess movement by rocking the wheel in and out. Do the same by rocking the tyre side to side. Any excessive free play should be checked out by a qualified mechanic. Also check the rear in the same manner. In solid rear axles you're checking for worn bearings and other damage.
Check your shocks for signs of leakage or damage or just plain worn out. You’re going to need those shocks.
Check your electrical and charging system. Ensure that your battery or dual battery system is functioning and that you will not drain the power overnight whilst camping. Carry along extra fuses, alternator brushes, dual battery solenoid, light bulbs and relays.
6. Plan the Trip / Inform Others
Tell those concerned where you are going, when you are leaving and when you’ll be back. Let them know when they should start to worry about you, if they haven’t heard from you. Give them contacts in case they need them. Prepare your trip. Have a map of the area you are going to and how you should get there (and home again).
Watch the weather for the region you are visiting and the route along the way. Be prepared with the appropriate clothing and protective gear (rain jacket, hats, sunglasses, lip balm, sunscreen). Pack extra clothing in case you get wet or it gets a little colder than expected. Even if you are not "planning" to stay the night, it’s good to have a sleeping bag. Its better to be over prepared than under prepared.
8. Necessities and Nature's Calling
Bring a roll of toilet paper packed in an air tight zip-lock plastic bag. In fact, ALWAYS carry a roll in your vehicle. When you need it, you’ll thank yourself for putting it there.
9. Communications to the World
Pack a cell phone and give it a full charge before departing. Pack the phone car charger. When you're remote and off road, you can still find a signal even if it’s atop a ridge or up a tree. Be aware that if your are out of signal range, your cell phone will be hunting for a signal and this will deplete your cell phone's battery quicker than just sitting in standby when in range.
10. GPS Navigating
A handheld GPS is a great thing to have. Prices have come down to the point that if you spend any time in the bush or off the road, you should have one. Hand-held units are easy to operate and once you are familiar with it, it can be a valuable tool to get you places. Should a real emergency arise, you'll learn quickly how valuable they can be. Bring spare batteries in a zip-lock bag and a car adapter for the GPS unit.
11. Communications Vehicle to Vehicle / Person to Person
Handheld walkie-talkies are very handy and inexpensive. They have great range and are very portable. Whether on foot or in the vehicles, it makes good sense to carry one. And communication can add to the fun and in the case of an emergency where the you need to temporarily split up the party, you do no want to be out of touch. If you have to separate, stay in range. CB and VHF Radio's also fall in this category but are less portable (most units stay with the vehicle)
12. Food / Water - Bring plenty of food and drink.
Even on the short trips. Bottled water, energy bars, and dried fruit, sports drinks, anything that has compact energy are good items to pack. Pack items that do not need refrigeration. Avoid salty foods such as chips and biltong, unless you have plenty to drink. And no, beer doesn't count! In fact it takes water to metabolize alcohol so the beer and liquor will dehydrate, not hydrate you. Alcohol is never a good idea when you have to think clearly.
13. Top up your Fuel
Fill the fuel tank prior to every trip. When you reach your destination, top it off again before going into a remote area. The last thing you want to do is start worrying about running out of fuel while off road. Remember the One-Third/Two-Third Rule: Use one-third of a tank to get where you are going and save two-thirds for getting out. If your fuel tank doesn’t have the capacity for the off road portion of the trip, carry extra fuel or re-think your route.
14. Transporting Fuel
Always carry your extra fuel outside the vehicle. Fuel containers have vents and petrol fumes are explosive and toxic.
15. Jumper Cables
Have a good set of jumper cables with heavy-gauge wire and quality connectors.
16. Recovery Straps
Bring at least one recovery strap, preferably 2 or more and make sure you have a place to hook it up on your vehicle front and rear. It’s also good to have extra pieces of recovery equipment such as a D shackles. If you have a winch, make sure you have winch related equipment such as a snatch block, gloves, bark protector, etc.
17. Belts and Hoses
Check all your belts and hoses, and carry spares. The lower radiator hose is the one that usually gets damaged while off roading, so ensure that you have a spare. Alternator/water-pump belts are the most important. Newer vehicles often use serpentine belts. While much less prone to failure, they can be difficult to change. They are also expensive, but carry one. Replacing an old serpentine belt and saving the original as a spare is a good idea.
18. Jack and jacking base plate
Make sure you have a working jack and know how to use it. A High-Lift jack is a great universal tool and also doubles as a winch (and lots more).
19. Spare for the Spare Tyre
If you have room, carry a second spare wheel. At the very least, carry a repair kit just in case. Nothing is worse than getting a second flat tire on the same trip.
20. Tool Kit
Carry a tool kit that covers the basics of your vehicle. Put your own together. Carry quality tools. See the Beyond the Basic: Recovery, Tools and for the Vehicle checklist!
21. First Aid
Carry a well equipped first-aid kit. See the Safety and Survival checklist!
22. Emergency Kit
Carry an emergency kit that covers any situation beyond first aid. This might include special medication, snake bite treatment, etc. See the Safety and Survival checklist!
Carry a flashlight/ torch and an extra set of fresh batteries. Also consider taking a work light to ensure you have light to work on your vehicle at night.
24. Driving off road
Establish the capabilities of your 4x4 in a controlled and safe environment before venturing off road or into a remote area. Learn how to get unstuck and recover your vehicle. Gain skills to ensure that you are competent to drive off road and stay within the limits of your vehicle.
25. Necessary documents
Depending on where you are travelling, it is often a requirement to have your vehicle registration, insurance documents and police clearance (if your vehicle is financed). Some countries also require a Carnet De Passage to allow temporary importation of a vehicle into a foreign country. Research your expedition and make copies of all the documents!