4x44X4 AdviceCar Advice

A Beginners Guide to a 4×4 Pre-Trip Inspection

If you’ve just purchased a brand-new 4WD and are planning a trip off-road, then this article is a must-read to ensure you get the most out of your new vehicle

SO, YOU’VE purchased a new 4WD, Congratulations – and you’re planning your first trip off-road, and the excitement is almost uncontainable. But, you need to temper that excitement and get a few simple check out of the way.

A pre-trip inspection is something we should all consider as good practice; from the beginner to the experienced off roader, it should be a part of every pre-trip preparation that minimises your chances of anything going wrong,ensuring things are mechanically and electrically sound. How much and what you check ultimately depends on both your experience and mechanical aptitude. And should you come across something out of the ordinary, it allows the time/opportunity to repair or replace before the big day or to seek further professional advice if you are unsure. Let’s begin:

Your pre-trip inspection should be take place at least four weeks before any planned off-road adventure so there is time to remedy any faults, particularly if you need to book the vehicle into a mechanic.

  1. Check that your headlights, brake lights, reverse lights and indicator globes are all working by getting someone to spot for you as you cycle through the switches. This is important as a basic safety feature on all vehicles, to warn other drivers should it be required: flash high beams should there be a danger on the road or a dangerous condition to other vehicles coming the opposite way;   should you get caught out longer than expected and end up driving at night, you want to see where you’re going,   and you always want to ensure the vehicle In your group directly behind you knows when you are braking to avoid any unnecessary incidents.Tip: When driving down very dry and dusty roads,   it always helps to put your low beam lights on, as this allows the vehicle behind you to see your tail lights through the dust, and the vehicle in front of you to see where you are via your headlights…dust can literally make a vehicle disappear from sight at times putting everyone at risk. It also helps a great deal with being able to see oncoming vehicles.

2.  Pop the bonnet. There are some simple items we can check to ensure reliability while off-road. I will detail them below:

  1. The obvious thing is to always check your engine oil. Pull the dipstick out, wipe the end with a rag, re-insert it fully and wait a second or two for the oil to accumulate around the end of the dip stick, then slowly pull it out and hold it towards the light…looking for the oil level in comparison to the “Min – Max” level indicators.

Tip: I would recommend to always fill to the top end of the “Full” indicator bar, as some vehicles can bring up an “oil light” on the dashboard if driving or parked at a steep angle for any period of time.

b. Always check the fan, alternator, power steering belts. If these look dry, cracked and beginning to fray, that is a sure sign that they are on the way out. Last thing we want is to lose battery charge, overheat, or lose power steering while off-road.

If the belts are loose, then tightening them in most cases is a simple process, or if unsure take it to a mechanic to do. How will you know if they are lose and need tightening? When a belt is loose, the most common sign is noise – ranging from a barely audible squeak to an ear-shattering squeal. It could happen when your idling, driving, or when turning your steering asking more of the power steering pump.

Tip: If the belts are replaced, it pays to keep the old one as an emergency backup in your tool kit or box of spares.

c.  Check the radiator overflow bottle is filled up to the “Full” level. If the engine gets hot and pushes the water out the bleeder hose, that is not a big issue. But should the radiator require to suck in more water and the reservoir is empty…that could pose an issue.

While we have the water bottle out, lets double check and fill the windscreen washer reservoir too. This is important, as when we are off-roading, our windscreen will get covered in dust a lot of the time and/or mud getting splattered. Maintaining a clean windscreen as we all know is pivotal to staying safe, hence we will use the windscreen washers more regularly than we would daily driving in town.

Whilst on the radiator, inspect the front of the radiator itself for any leaks out of the front, and if the radiator itself is blocked with grass, bugs or other foreign objects, this may affect the performance of the cooling system as it would prohibit sufficient airflow through the fins to cool the water internally as required.

For vehicles fitted with a top-mount or front-mount intercooler, the same inspection and cleaning principles would apply.

Tip: A splash of coolant into the reservoir doesn’t hurt to ensure it has the required properties to assist cooling if adding clean water.

Tip: A squirt of dishwashing detergent into the windscreen washer reservoir help with cleaning bugs off the front screen.

Tip: And a soft paintbrush is a useful tool to use to help you clean out bugs out of the front of the radiator…DO NOT USE A HIGH PRESSURE CLEANER as this will bend the soft alloy fins blocking their ability to pass air and cool.

d. While we are in the engine bay, let’s also check the brake fluid reservoir as well as the power steering fluid reservoir. These are pretty basic in inspection; the brake fluid reservoir has clearly defined level indicator on the outside and the power steering fluid reservoir has a dip stick built into the underside of the cap itself.

Tip:  If unsure of any of the fluid specifications, the back of the vehicles Owner’s Manual clearly defines what fluid specifications should be used, and asked for at the auto store.

Tip: Always have a rag and some brake cleaner spray ready when topping up the brake fluid.   Brake fluid is corrosive in nature and spilling any on your paintwork will result in the paint flaking off and peeling. Thus, spraying brake cleaner and wiping down with a rag helps – detergent and warm water is also good.

e. To conclude an inspection of the engine bay, you should check the battery. Start off by checking the battery clamp is tight. We do not want the heavy battery moving around whilst we are off-roading. Then check the positive and negative terminals are clamped on tight. If your battery allows it (some are sealed by design), undo the battery cell caps, and have a look inside to ensure that the cell walls are covered in liquid (distilled water). If they are not, carefully top them up, but only enough to “just’ cover the cells, before screwing the caps back on.

To protect the terminals from oxidation, we can cover them with a little bit of grease. Why do the terminals oxidise? Because the terminals are usually made of lead or some other highly conductive metal, that is heavy-duty in nature, but still offers low electrical resistance. Because the terminals are in direct contact with the battery they are exposed to the acidic fumes from the battery acid and as a result are prone to developing corrosion. If your terminals are oxidising (powdery blue or white corrosion), you will not get effective power flow through your cables. Symptoms may include experiencing difficulty starting, slow cranking, or rapid clicking when the ignition key is turned. If the corrosion is bad and difficult to remove, you may need to replace the battery terminals which is a simple enough exercise. If running a dual battery setup, the same inspection procedure applies to the second battery, though sometimes the second battery is a sealed unit so cannot be inspected .

Tip: Battery fluid is corrosive and can be explosive if ignited via spark – always ensure there is no naked flame nearby,   wear eye protection and rubber protective gloves.

3.   We wouldn’t be able to off-road unless we look after our wheels and tyres. So, we should inspect the condition of them to ensure they are safe. Ideally, we would remove the wheel/tyre off the vehicle so that we may check the inside side wall of the tyre (Please refer to the vehicle’s owner’s manual on how to safely jack up your vehicle – please use jack-stands). Once the wheel has been removed, we roll the tyre and ensure:

a. The tread is of a safe depth. This should be no less than 30% of the original tread depth, and 50% if you’re planning on a long outback trip. The legal limit is 1.5mm, which is for road car tyres with a small tread depth to begin with, not deep-tread off-road tyres. Also check the wear across the tyre is even, if not have your wheel alignment checked.

b.  There are no foreign objects embedded in the tyre that could potentially deflate it if removed or ripped out.

c.   Check the sidewalls on both side of the tyre to ensure there are no splits, bubbles, or foreign embedded objects here too.

d.   Check the bead (lip where the tyre meets the wheels,) to ensure it is not torn, chunks are missing or damaged.

Tip: It is a good opportunity to remove your spare wheel as well to inspect it, and ensure it is pumped up a little more than normal, as the spare tyre can be forgotten at times, and you will want that spare tyre to be in an operable condition should the situation arise where it is required.

4.  While the wheel is off, take the chance to stick your head underneath and inspect the brake pads and disc rotors. With the disc rotors, you’re are looking to ensure there are no “blue” hot spots on the brake disc or cracks due to heat, and on the brake pads we are checking to ensure they have enough material and are not worn down past the indicators…in which case the services of a mechanic might be required.

5. Another item we should inspect while the wheel is off is the suspension components of the vehicle. Primarily simple inspection items such as CV boot rubbers to ensure they are not ripped or damaged. Ball joint boots have not split, and steering rack boots as well. These are easy items to check.

6.  We now re-fit the wheel/tyre back onto the hub, and ensure we tighten it, but not too tight, utilising the star pattern to ensure the wheel tightens up to the hub evenly.

Tip: Never use WD-40 or similar oil sprays on the wheel studs to help tighten the wheel nuts – this increase the tightening torque and can lead to wheel stud breakages by stretching the wheel stud over time.

7.  If you have a winch, it would pay to familiarise yourself with its operation. How the brake releases; pull the line out all the way, and with someone assisting you to operate the winch, wind the cable back in slowly and neatly from left to right and back again and so forth .This goes for all recovery gear.

8. Finally, before you go off-road and have to utilise the vehicle in low-range, try and find a paddock nearby, some gravel road, grass, basically any low traction surface to test out that everything engages and works in low range:

  1. Check the front freewheeling hubs, that the switch operates nice and smoothly;
  2. Check that the low range shifter (or switch) engages smoothly and properly; and
  3. Check that any cross-axle differential locks if fitted operate as they should.

Tip:  Always ensure your transmission is in neutral before selecting low range to engage it properly.

So, there you have it. You have just completed your first 4WD pre-trip inspection. Well done. It may seem quite involved but, as you go on, and familiarise yourself with your vehicle, it will eventually become second nature and the time to action all the checks will reduce…you may even find there should be additional items that need checking, or different vehicles require different things to be checked.

All in all, this is about “Safety”, “Reliability” and ensuring you have a great time off-road wherever your vehicle may take you.


  • dilligaf

    Good tips. Just a couple more, (I know, keep it simple) when checking the oil, make sure the vehicle is parked on level ground. Just before removing the wheel check for bearing and steering play.

    • Yep good points again diligaf. And how do you know what ‘normal’ is when checking for things like steering play? You compare against all the other times when you know it’s good, and asking your mechanic (4×4 specialist only) to help is a good idea too.

maxf

maxf

Max has 21 years of experience with Toyota Motor Corporation Australia. A Toyota qualified Automotive Technician, now working as Technical Officer in the Parts & Accessories Risk Engineering Group.

Also owner and operator of Hillside Offroad and a huge Hilux enthusiast.