4WD Driving Skills: A Manual for On- and Off-Road Travel

Preface

I vividly remember my first 4WD. That was way back in 1978. There were no 4WD training schools to attend, recovery gear was all but non-existent and I learned my 4WD skills the hard way. In those days I spent many scary moments behind the steering wheel on a lonely 4WD track deep in the forests of the east coast of Australia.

Now at the helm of one of the country’s leading 4WD training schools and tag-along tour companies (Great Divide Tours), it is amazing how much things have changed and yet remained the same. I see in the eyes of my clients that same wide-eyed look of fear of the unknown that I often experienced myself. Now they have the benefit of gaining knowledge that only years of 4WD experience can ever teach. The array of recovery gear that is available, the quality of the products and the technology that our modern 4WD vehicles now embrace are among the best in the world.

Having conducted literally thousands of 4WD training courses and being responsible for teaching the skills of handling a 4WD to more people than almost anyone else in the country, let me assure you that there is an art to safe four-wheel driving. One does wonder if we will ever get to the point of driverless vehicles and although this may become common practice in our major cities it is hard to believe that the future could see us sitting in the rear seat of our 4WD as it traverses the dead heart of the country.

The advancements made in 4WD vehicles and the corresponding explosion of interest in this type of vehicle continue to accelerate and show no signs of diminishing. If anything, the proliferation of adventure travel television shows and the improved reliability and capability of vehicles has added fuel to their popularity. There is no doubt that more and more people are getting away from the city limits every year.

Coupled to this is the pressure on the employer to provide a safe workplace and the need to provide appropriate training in the handling of fleet vehicles in all types of terrain. The Workplace Health and Safety issues of working with 4WDs and their associated recovery equipment cannot be overlooked.

With the training courses and the 4WD tours that I conduct, I am literally away every weekend using my 4WD for its intended purpose. My own 4WD exploits have taken me to every corner of this incredible continent, as well as overseas in places such as New Zealand, Africa and Iceland. I can assure you that this massive amount of experience has helped me enormously in the preparation of this book. I urge you to look at <www.4wd.net.au> for some insight into my background and experience on all things related to four-wheel driving.

This is my third book and now its second edition, updated with all the latest technology now found in the modern 4WD, things I have learnt to make vehicle recovery even more safe and now it covers all the various units of required learning in nationally recognised courses associated with the use of 4WD vehicles and their associated recovery. This allows this book to be used by presenters of nationally recognised training courses in this field as their manual of operations.

My two other books include Travelling the Outback, which was aimed at recreational four-wheel drivers who had purchased their 4WD and were planning that once-in-a-lifetime journey. My second book, Classic Outback Tracks, detailed some of Australia’s best known 4WD destinations.

This book, 4WD Driving Skills, was first published in 2001 and has been reprinted several times over the intervening years, but it’s time it was updated to keep up with the changes in vehicles, so here is the latest version of how to safely drive your 4WD vehicle on and off the highway.

Vic Widman

For all your 4WD training needs contact Vic at [email protected]

Vic Widman.

1

Introduction

I am now a firm believer that driving a 4WD does require a new set of driving skills over those taught to us during our standard learner driver training. Let’s face it, to achieve your driver’s licence for a light vehicle, whether that be a 2WD or 4WD, you are not trained or tested in the differences between a 2WD and a 4WD. Nor are you shown how the 4WD system works on your particular vehicle or even tested in an off-road situation. So how can we expect a person that has held a licence for a week or for a lifetime to understand anything about traction control, picking the correct line, track assessment, not to mention what a safe recovery point is or why it’s imperative to use an air brake when winching? So let’s start with the differences between these vehicles: the very basics that simply are not covered when we all obtained our driver’s licence.

1.1 Comparing 2WD and 4WD

A 2WD vehicle does not offer 4WD traction, it does not have the same under-body clearance as a 4WD and it does not have the heavy-duty construction of its running gear (differential, axles, drive train, wheels) as a 4WD. As a consequence of this, a 2WD is lighter and has a lower centre of gravity, which means it will accelerate comparatively quicker, will stop quicker, handle better and use less fuel than a 4WD.

2WD vehicles are very different from 4WD vehicles.

An interesting trend these days is that some manufacturers are now producing motor vehicles that look exactly the same in 2WD, AWD (all-wheel drive) and 4WD models.

1.2 Sports utility vehicles (SUVs)

The transition from 2WD to 4WD vehicles is becoming more blurred with the advent of what some people term ‘crossover’ vehicles or SUVs. These are vehicles that may possess AWD or 4WD capability but have a much lighter construction and drive train than a more traditional 4WD. There is no doubt that these vehicles are more user-friendly in terms of the transition to a 4WD, but they do not have the same capability as what is best termed a real 4WD.

To try to explain that comment, a real 4WD might be seen as one with raised ground clearance, more robust under-body components such as differentials, drive trains and even stronger bash plates under the vehicle. In some vehicles this includes the addition of lower gearing, more traditionally known as low range. However, even this is not always the case with some 4WD vehicles now only having a single range transmission that has been equipped with a lower than normal ratio first gear and loads of technology to help it get by in rough conditions.

There is certainly some common ground between some AWD and 4WD vehicles in terms of their operation in 4WD and the skills needed to drive them on certain tracks. However, there are also major differences between light-duty and heavy-duty 4WD vehicles that need to be understood. Each of this type of 4WD has its advantages and disadvantages. It is only when a driver either confuses the vehicle’s role or expects either type of vehicle to perform in a way for which it was never really designed that drivers find their vehicles wanting or letting them down.

1.3 Light-duty 4WD and heavy-duty 4WD vehicles

The blurring of the transition from 2WD to 4WD is confusing to some people. It is vitally important to understand the basic differences between a light-duty 4WD vehicle and a heavy-duty 4WD.

Most light-duty 4WDs will provide what is best termed as all-wheel-drive traction. They possess a single range transfer case that offers normal driving speeds but with all-wheel-drive traction. They will rely on technology via traction control and vehicle stability control to provide greater road holding capability over a traditional 2WD. The light-duty 4WD also offers less underbody protection, such as plastic sump guards and fuel tank protection plates, which may even be lacking.

The light-duty 4WD offers car-like performance and handling through its more conventional sedan-type suspension and steering. These vehicles do provide more ground clearance than a conventional 2WD vehicle, more interior space and the better ride height enjoyed by the more traditional 4WDs. These are the great advantages of the light-duty 4WD, as well as a perceived safety aspect through improved visibility, strength of the vehicle and all-wheel-drive traction.

The heavy-duty 4WD is easily identified by its more rugged underbody protection, where steel plates replace the lighter plastic covers. The heavy-duty 4WD will offer (in most cases) a dual-range transfer case that provides vastly improved performance on unsealed tracks that are severely rutted or extremely steep. These vehicles perform exceptionally well in rugged, mountainous terrain or on long outback hauls where the constant pounding of corrugated roads is soaked up by the strong steering and suspension components. However, around town, these same characteristics of heavy-duty construction and truck-like gearboxes can make these vehicles a real handful when the daily chores around the supermarket are being attended to.

A typical all-wheel drive vehicle.

The light-duty 4WD will perform exceptionally well on a bitumen road in the wet, or on a well-graded unsealed road and in light snow. However, this same vehicle has not been designed to climb mountains, ford streams and blast across the farm to reach that back paddock to muster the sheep. This is the domain of the heavy-duty 4WD with its dual-range transfer case and more rugged construction.

As mentioned in the previous section, there have been enormous changes in the 4WD vehicle market in recent times. There is no doubt that this will continue as the huge sales figures of vehicles that offer 4WD traction continue to grow. The trend to sway towards the offering of light-duty 4WD vehicles (i.e. a vehicle that may have 4WD traction that is ideal on wet, greasy bitumen or even a good unsealed road) is likely to continue. However, these light-duty 4WDs were never designed to venture into ‘real’ 4WD terrain where the roads are washed out, steep and little more than a dozer blade cut through the forest. This needs to be considered when you are choosing the right vehicle for your private or business use.

Over the past decade we have seen the greatest advancement and changes made to the drive systems in 4WD vehicles. This trend is very likely to continue. Even attempting to write an explanation of what is available out there today is fraught with problems due to the large variety of 4WD systems already available. I have even seen completely different 4WD activation systems within the same make of vehicle and have seen this change from one year to the next within the same make and model. So, despite doing my best to explain the various 4WD systems currently available, I also strongly recommend that you read your owner’s manual and attend a nationally recognised 4WD training course to learn exactly how to get the most out of your particular vehicle.

Here we see all styles: 2WD, AWD and 4WD.

1.4 What is a 4WD system?

Because of the existence of many different activation systems of 4WD, it is best if we first understand what is meant by this terminology. To do this, let me first talk about the traditional 2WD motor vehicle that makes up most of the vehicles on the road at present. A 2WD diverts drive either to the rear wheels or the front wheels only. The wheels at the other end of the vehicle receive no driving force from the motor. If a 2WD vehicle is driven on slippery or uneven ground and the wheels receiving the driving force from the transmission lose traction then the vehicle immediately ceases forward progress. In fact, it only needs one wheel to lose traction and all the drive is then sent to that one wheel and no forward progress is possible. This is a very important fact to remember.

A vehicle with 4WD capability allows drive to be sent to the front wheels and the rear wheels of the vehicle at the same time. However, this is where many people become confused about the real meaning of 4WD. The mere name implies that all four wheels receive driving force all the time but this is not always the result. Say for example in a 4WD vehicle one of the front wheels passes over a deep hole and actually leaves the ground, that wheel will receive all the drive going to the front of the vehicle. The opposite wheel that remains on the ground does not receive any of the drive. If one of the rear wheels also loses traction due to another deep hole at the same time, then all of the drive going to the rear of the vehicle will be diverted to the wheel with the least resistance, in this case the wheel that has lost traction. With all the drive at the front going to the wheel with no traction and all of the drive going to the rear wheels going to the wheel with no traction, the vehicle cannot move forward. So despite calling this vehicle a 4WD, we can see how only two wheels will receive drive if they don’t have traction. The result is the vehicle is stopped in its tracks!

So now we can see why later in this book I talk so much about maintaining contact with the ground at all times with all wheels. I call it maintaining traction. This is done through assessment of the terrain over which you are driving. If all four wheels remain on the ground and remain on a non-slip surface, then all four wheels receive the driving force and the vehicle continues forward progress.

Fortunately the advances in technology that I wrote of earlier are now tackling the issue of lost traction and may assist the vehicle in the above situation actually gaining traction and moving forward. This is explained in the section on traction control and differential locks.

1.5 What types of 4WD systems are available?

AWD vehicles are those with all-wheel drive capability that generally speaking do not have a centre differential that can be locked, which diverts drive equally to the front and rear wheels. They can be driven on a non-slip surface (e.g. a sealed road) in AWD without causing damage to the transmission. They are not very capable in off-road terrain where the ground is rough and uneven. They do not have very strong under-body protection or drive line components, therefore, they are used more for highway and some gravel or snow driving.

Constant or full-time 4WD vehicles can be confused with AWD vehicles, but generally they provide more robust and stronger drive line components and under-body protection. Some constant 4WD vehicles can lock the centre differential, which means by selecting this drive line capability it directs 50% of the driving action to the front wheels and 50% of it to the rear wheels. It is vitally important that the centre differential is locked when negotiating 4WD terrain, otherwise the vehicle is not in 4WD but rather AWD. However, there is a growing trend among vehicle manufacturers to take this decision away from the driver with the amount of drive going forward and rearward being determined by the computer systems in the vehicle. The driver has some control over this in some vehicles by selecting different styles of terrain, such as gravel, sand, mud or rocks. This is generally known as a terrain response system. Each of those selections alters the sensitivity of the traction control system within the vehicle (see Section 1.15).

Part-time 4WD is when your vehicle offers the choice of 2WD and 4WD. This simply means that when in 2WD the engine is driving one set of either front or rear wheels only. When 4WD is selected, the drive from the engine through the transfer case is split between the front differential and the rear differential (generally a 50% split each way). This is the same result as a constant or full-time 4WD when the centre differential is manually engaged by the driver.

1.6 Vehicles with free-wheeling hubs

Vehicles that offer both 2WD and 4WD capability (referred to as part-time 4WD) may be fitted with free-wheeling hubs. These are found on the hub of the front axle in the centre of the front wheel. They are identified with ‘Free’ and ‘Lock’ or ‘4×4’ and ‘4×2’ stamped on the steel case of the hub. Free-wheeling hubs are fitted to both front wheels. They are never fitted to rear wheels. When in the ‘Free’ position the hub is disconnected from the front axle. Therefore, if you do select 4WD on the transfer case but neglect to lock the hubs, then the drive going to the front wheels will not reach them and your vehicle is still delivering drive only to the rear wheels.

A free-wheeling hub.

If your 4WD has the option of free-wheeling hubs, you can do no harm to your vehicle if you leave them in the ‘Lock’ position and drive around town in 2WD. There will be marginally more wear and effort required by the motor to turn the hub and axle (which is connected to the differential and the front drive shaft), but there is no drive going to these components when the transfer lever is in the 2WD position.

If you rarely use 4WD and have free-wheeling hubs fitted, it is actually a good idea to occasionally lock the hubs and drive around with them in this Lock position for a few days. This assists in keeping the grease healthy in the hubs. When doing this do not select 4WD when driving on a non-slip surface (see Section 1.10).

My advice to those of you with a 2WD/4WD vehicle that is fitted with free-wheeling hubs is to have the hubs in the Free position while driving around town and on long bitumen journeys. When you reach the unsealed section of road move your hubs to the Lock position, and don’t forget to do so with both front hubs; visually check that the slot is pointing to the Lock position. (This is necessary as you might actually be unlocking the hub where it was already in the Lock position – kids do change things when you’re not looking!) Leave the free-wheeling hubs locked while you are likely to do any unsealed road driving. You can now move between 2WD and 4WD as required. When you leave the unsealed road for the last time, stop and move your free-wheeling hubs to the Free position for the drive home.

1.7 2WD/4WD vehicles without free-wheeling hubs

Several 2WD/4WD (part-time 4WD) vehicles do not have the option of manually operated free-wheeling hubs. Instead they may offer a combination of no choice at all, an electronically controlled system, which activates once 4WD is selected, and even a combination of automatic selection with manual override.

With these vehicles, the selection of 4WD is simply a case of either moving the transfer