4 Guide to Four Wheel Driving
- FileName: Guide_to_4WD.pdf
4 Guide to Four Wheel Driving
How to use
This Guide was prepared in Collaboration with
the UNHCR e-center: www.the-ecentre.net the vehicle effectively,
for safe driving.
TOYOTA MOTOR CORPORATION Four Wheel Driving
TOYOTA MOTOR CORPORATION
Copyright 2001 Toyota Motor Corporation. All rights reserved.
use the vehicle
for safe driving. 1 Basic Information for 4WD
In this manual you will find basic 4 How 4WD Works
5 Using 4WD Vehicles
information needed to operate a 8 Basic of Off-road Driving
4WD. Even if you are an experi- 2 Driving Techniques
enced 4WD user, you will probably 11 Hill-climbing
13 Down-hill Driving
find some information in here you 14 Ditch
didn’t know or be reminded of 16 Slope
something you may have forgot- 17 Muddy Soil
ten. In any event, please enjoy 19 Sandy Soil
reading through this manual and 20 Rocky Surface
learning or re-learning the benefits 21 Snowy Surface
of owning a Toyota 4WD. 3 Remarks
28 Winching Techniques
30 Inspection before Driving
32 Inspection after Driving
Basic Information for 4WD
How 4WD Works Using 4WD Vehicles
The mechanism and characteristics of Using 4WD vehicles
four-wheel drive (4WD) vehicles
Most cars on the road today move move the vehicle even if one of the
by using two wheels, either on the wheels doesn’t have traction. 4WD
rear (RWD) or on the front (FWD) gets more traction than RWD or 2WD 1 FWD: Front Wheel Drive
of the vehicle. 4WD, on the other FWD and ensures stable driving 2 RWD: Rear Wheel Drive
hand, uses all four wheels. By off-road—on sandy, muddy or
mobilizing all four wheels, it can slippery surfaces.
The Difference between 4WD and 2WD
4WD 1 Full Time 4WD: Permanent 4WD
The vehicle utilizes all The vehicle loses 2 Standby 4WD: Usually 2WD, becomes
four-wheels to propel it. momentum. 4WD automatically when it is necessary.
The fron 3 Part-time 4WD: Usually 2WD,
not clim wheels can- becomes 4WD by the driver’s choice.
RWD b the ga
(drive) sl heels
(drive) g ar wheels
RWD et ca
the gapught in
1 Basic Information for 4WD
4WD mode Locking the front free-
With full-time 4WD, no action is necessary. With part-time 4WD, drivers Shifting the gearbox to 4WD mode in reverse motion to do this. So it is
must lock the front free-wheel hubs and shift into four wheel drive. is only half of the procedure to not possible to do this if the car is
actually engage all of the wheels. stuck. These vehicles require the
Sub-transmission The front drive shaft has to be con- driver to lock the front free-wheel
nected to the front wheels, too. hub in advance.
There are two types of 4WD regarding transfer. There are three types of connec- 3 Automatic: The locking of front
1 Transfer lever type: Shift the lever to “H4” or “L4”
. tions here. free-wheel hub is done while the
2 Switch type: Push a switching button. 1 Manual: Rotate the dial of the diver shifts into 4WD mode.
front free-wheel hub into “lock”
2 Power Locking: Push the hub-
lock switch button. Some 4WD
vehicles with power-locking con-
nections require the vehicle to be Power Locking
As a general rule, shifting into 4WD is to be done while the car is parked.
Yet, there are types of 4WD that allow the shifting to be done while the
vehicle is in motion. Confirm the appropriate procedure (by consulting the
operation manual) so as not to damage the vehicle and to avoid accidents.
When the shift is made, usually an indicator lamp lights up to confirm the Hub Lock
shift. However, the lamp can fail and driving the car is a better way of con- & H4 button
firming that the shift into 4WD has taken place.
1 Basic Information for 4WD
Basic of Off-road Driving LSD & Differential lock or "L4" with the free-wheel hubs
system engaged to see if it works. If this has
DRIVING POSITION DRIVING CONDITIONS
LSD (Limited Slip Differential) no effect,also use the front and rear
2WD H2: Lever at "H2" Use this for normal driving on dry, hard-sur- Some vehicles are equipped with a differential lock system.
faced roads.This position provides better limited-slip differential. If one rear 2.Do not use the front and rear dif-
(High speed position, economy, a quieter ride and the least wear.
two wheel drive) wheel begins to spin, the limited ferential lock in conditions other
slip differential automatically than the above as it will make
transfers the drive the other rear steering and cornering very diffi-
4WD H4: Lever at "H4" Use this for normal driving on wet, icy or wheel. cult. This is especially true when
snow-covered roads.This position provides Differential lock system using the front differential lock in
(High speed position, greater traction than two-wheel drive.
four wheel drive) Some vehicles are equipped with a addition to the rear and may cause
front or rear differential lock system. the vehicle to spin suddenly during
1. This differential lock system is acceleration or engine braking.*
4WD L4 Use this for maximum power and traction. effective in case one or either right
Use "L4" for climbing or descending steep *Engine Brake: By backing off the
(Low speed position, hills, off-road driving, and hard pulling in or left pair of the wheels is spinning. accelerator, you can use the engine to
four wheel drive) sand, mud or deep snow. Before using the front and rear dif- help you brake. The resistance, of the
ferential lock system, first shift the slowing engine,slows the wheel speed
and effectively slows the vehicle.
four-wheel drive control into "H4"
Driving slowly Tight corner braking and rear wheels. While this is not a
when using L4. phenomenon malfunction,driving on a road with
When driving in 4WD, making a good traction could result in worn
sharp turn can feel like the vehicle tires and damage the mechanism .
is blocked. This is called tight cor- It should be avoided. Driving with-
ner braking phenomenon and is a out the center differential locked
result of the difference in the rota- helps avoid this problem.
tion speed required for the front
Hill-climbing run, an alternate route should be
used. However, an approach run
SITUATION CHECK POINTS TO JUDGE GEAR SELECTION Approach run
THE DRIVEABILITY should be restrained to gapless sur-
faces. When there is a gap on the
Hill Climb Angle, Length, Surface (hardness, Gear which requires If the slope is steep or has a slippery surface it is better to climb slowly
solidity, gap, slipperiness) Drop or no shift change surface, making an approach run and steadily to reduce the shock to
curve at the top of slope could reduce slip while climbing. If the under body.
Down Hill Angle, Length, Surface (hardness, Use a lower gear to there is no room for an approach
solidity, gap, slipperiness) get the maximum
engine brake Choose in advance the route
with the least gaps .
Ditch Width, Depth of ditch, Angle,
Surface (sand, stone, mud, solidity)
Slope Angle,Width, Distance, Surface
Muddy Soil Angle,Width, Distance, Surface Use a lower gear
(solidity, existence of track or gap)
Keep the speed
River Depth,Width, Distance, Speed of L4 steady…
The vehicle can end up
the flow, Bottom making a big leap oth-
(Stability, solidity, gap slipperiness) erwise.
Sandy Soil Gradient, Distance Surface L4
(solidity, gap) 2 Long climb: When climbing a
Tips for driving
Rocky Surface Gradient, Distance Surface L4 long hill, keep the speed steady.
(solidity, gap, slipperiness) 1 Speed, distance and direc- 3 Clutch operation: It is best not
tion: Make an approach run at an to shift. However, if a change is
Snowy Surface Gradient, Distance Surface Use a higher gear adequate speed and from suffi- required on the way, do it quickly
(iced, gap, hidden object under when starting and a cient distance. Climb the hill and with little clutch use to avoid
snow) lower gear down hill
straight towards the top. losing momentum and traction.
2 Driving Techniques
4 Acceleration: Use a steady If the wheels lose traction because straight down the hill. If the tires
Down-hill lose traction, slightly accelerating
acceleration up the hill and back the surface is slippery , slightly Driving
off the acceleration towards the decelerate to bring the traction can help regain traction and steer-
top to avoid shooting over the top. back. Tips for driving ing control.
3 Long slope: Vehicles tend to
1 Gear selection and braking: gain momentum as they go down-
Recovery rear-view mirror to guide your Choose a low gear to take advan- hill. Regardless, try to maintain a
descent. It is best not to use the tage of engine braking and to be steady speed.
If you slip before reaching the top, foot brake to avoid tire-lock. How- able to avoid using the brake. On a 4 Clutch operation: When driv-
back up using the engine as a ever,brake gently to keep the vehi- steep or slippery slope, choosing ing down-hill, don’t clutch, as it
brake. This is your recovery. Keep cle under control* in cars with “L4” to get the maximum engine will nullify the engine brake. This
the steering wheel pointed toward automatic transmissions due to brake is appropriate. Of course the causes loss of traction and acceler-
the top of the slope and use the the lack of enough engine braking. conditions and type of vehicle ates the vehicle. It is one of the
(manual or automatic, etc.) may most dangerous things when driv-
necessitate foot braking. ing downhill.
Use the 2 Maintain the direction:
Make a careful
recovery when an engine to Down-hill driving should aim Avoid operation of the
attempt fails. brake. clutch or changing
Before driving a down-hill, speed.
Back up straight and check the surface condition and
avoid locking tires. choose a gear that is adequate
to the gradient.
*Vehicles with ABS** allow the **ABS: The ABS (Anti-lock Braking
application of even full-braking System) prevents wheel lock-up
though full-braking may require a allowing the driver to take evasive Make absolutely sure
longer distance to come to a full stop. action while braking. to keep the vehicle
2 Driving Techniques
Driving over a
Tips for driving
body. It is important at this time 2 Driving speed and accelera- 3 Mitigate depth or slope:
1 Approach angle and drive that at least three of the tires tion: Slowly enter one tire at a When the depth or the angle is too
path: Approach ditches/holes at maintain traction. Be sure to use time into the ditch/gap. Then, great, adjustments could be made
an angle for maximum control. full-time 4WD with center differ- accelerate a little until the tire by placing a rock or other object
Direct approaches could result in ential activated when driving in starts to pass the lip and decelerate where the tires hit.
hitting the bumper or underguard these conditions. right after the tire clears the ditch.
against edge of the ditch. The Caution: If your angle is wrong, two Repeat this process for all four
angled approach increases clear- tires may enter the ditch at the same tires. On a slippery surface,
ance. The angled approach also time, which could cause you to get increase or decrease speed as
forces tires into the ditch one by stuck. Drive carefully. needed.
one, reducing the impact to the
Apply the tire to the “wall” of a ditch/gap and then accel-
erate gently to bring the tire over the “wall”. Decelerate
right after the tire goes beyond the “wall.”
Approach a ditch
slantwise and drop
the tires one by one.
2 Driving Techniques
Driving over a Slope Driving through Muddy Soil
Tips for driving Avoid frequent gear Tips for driving
1 Approach angle: 1 Driving path: 5 Adjustment of tire pressure:
Use different approaches should Only drive through shallow mud On a muddy surface, mud can stick
be applied depending on the cir- (the depth should not go above the in the tire tread which reduces
cumstance.Given a choice, howev- center of the differential); remain traction and the vehicle can easily
er, keep the driver’s seat closer to on as solid a surface as possible. get stuck. To prevent this , reduce
the mountain side gives the driver tire pressure to the level of 1.2
an increased sense of security. 2 Gear selection: kg/cm2 to 1.5 kg/cm2.This increas-
Choose the gear one lower than es traction. If the mud is very wet,
The driver’s seat should
the one capable for managing the increasing the tire pressure could
be mountain side to surface. If the vehicle is equipped increase the traction by making
help prevent panic and with a differential lock system, mud less likely to stick on the
feelings of vertigo. activate it. tires.
2 Driving speed and acceleration: 3 Clutch operation: Maintain a
Steady acceleration or a constant speed speed in which traction is not lost
is best. and do not change gears. Shifting
can result in sudden deceleration
Steering to the mountain side could Steer to the valley side to adjust the
cause a roll over. direction of the vehicle. and make the vehicle stick in place.
4 Steering operation: Utilizing tire chains
Rotating the steering on muddy
surface causes increased resist- On a muddy surface,consider using
ance. Keep the direction constant. tire chains.
2 Driving Techniques
Driving through Driving through
a River Sandy Soil When the vehicle is stuck, lower
the tire pressure to make the
Tips for driving Tips for driving restart easier but don’t forget to
add pressure afterward.
1 Approach angle and driving 1 Traction and tire pressure: In
path: Choose a downstream path. Avoid shifting to get sandy soil, the sand is soft and the
up and down.
Going against the flow could stop resistance is high.Similar to muddy
the vehicle. Also avoid anywhere soil, gaining traction in sand is dif-
deeper than the center of the tires. result in the vehicle getting caught ficult. In order to avoid getting
In shallow places where the in a gap at the bottom. To guard stuck, reduce the tire pressure.
stream is slow,you must be careful against such an incident, your However,too much reduction could
of mud and sand accumulations. thumbs should not be placed cause the tires to separate from the
Water is deeper than it appears, so inside the steering wheel. rims causing a whole new set of
If the vehicle stops, turn
add 20 to 30% to the depth as it 4 Selection of landing area: The problems. the steering straight
looks from the surface. landing area should be a point 2 Gear selection: Considering the before restarting.
2 Gear selection and speed: with a solid surface and a small strong resistance, “L4” is a good
“L4” is a good choice and constant vertical gap. (Many vehicles get choice. If the vehicle is equipped
acceleration prevents water from stuck at the landing point.) with a differential lock system, sion is thus preferable over manual
entering the muffler and the activate it. transmission as it doesn’t require
engine. Water entering the air 3 Steering and clutch opera- the driver to use a clutch.
intake or electrical system would tion: Don’t turn suddenly.Stepping 4 Stopping a vehicle: Applying
cause water-hammer* or a short- *Water-hammer: If a quantity of on the clutch could get the vehicle brakes will sink the vehicle. There-
circuit. water coming into the combustion stuck. Therefore, use a gear which fore,let the vehicle stop by itself or,
3 Steering operation: The bot- chamber exceeds its capacity, proper will take you through the entire even better, stop the vehicle on a
compression stops. This may cause a
tom may not be visible because of connecting rod to bend or even break trip without shifting. If you must solid surface or at a high position
mud or sunlight reflected on the and may also damage a piston. shift, do it quickly so as not to lose so that restarting on a downhill
river surface. Such situations could momentum. Automatic transmis- slope is possible.
2 Driving Techniques
Driving on a Rocky Surface Driving on a Snowy Surface
Tips for driving traction is required.However,high- Tips for driving traction. To start a vehicle, engage
er pressure is required most of the the clutch gently and gradually.
1 Gear selection and speed:“L4” time in order to minimize the pos- INSPECTION OF THE SURFACE Select a higher gear, too. With an
would be the right choice to drive sible damage by the rocks to the 1 As dangerous objects could be automatic transmission vehicle,
through steep and rocky surfaces. tire and wheel. underneath the snow, walk on the simply release the brake pedal to
Drive at a walking speed.Fast driv- 4 Steering operation: In prepa- surface to test it before driving start the vehicle in motion.
ing kicks up stones which can ration against the kickback from through snow.
damage the vehicle, while impact the rocky surface, place your 2 The maximum depth of snow DRIVING SPEED
from driving over a gap could thumbs on the steering wheel. A you should drive through is up to On a road with an icy or snowy sur-
damage the wheels or suspension. firm grip is necessary to avoid the differential. If the surface con- face,drive at less than half the reg-
2 Driving path: It is best to have straying from the chosen path. sists mostly of new, dry snow, the ular speed.
an assistant guide the driver for maximum height could be up to
safety. Look for sharp rocks which the bumper. Anything deeper STEERING OPERATION
can damage the wheel or burst a requires the vehicle to repeat the 1 Use studless tires* when driving
tire. When driving over rocks, process of pushing the snow and through snow. Over confidence of
make sure they can’t move. If a Ask an assistant
then backing up. driving a 4WD could lead to the
rock tilts when initially touched, it to guide the driv- 3 The quality of the snow would vehicle getting stuck or to an acci-
could lodge under the body of the er. change its resistance. Vehicles can dent. Once the vehicle loses trac-
vehicle or could give way causing a get more easily stuck in wet and
* Studless Tires: The specific tire for
roll-over. icy snow. driving on an icy or snowy road.The
3 Tire pressure: Lowering the 4 Some vehicles get more stability main benefit of this tire is its ability
pressure is an option when better by driving through a track left by to keep elastic in cold temperatures,
previous vehicles. which in turn improves its traction.
The tread of this type of tire is specif-
Driving at high ically designed for smooth driving
speeds is always
STARTING THE VEHICLE
dangerous. Abrupt clutching results in loss of on icy or snowy roads.
2 Driving Techniques
tion, there is no difference mentum. Therefore, the vehicle Tire chains
between 4WD and 2WD. speed should be lowered before
2 Making a sharp turn is danger- cornering. 1 Tire chains: There are metal
ous. If the vehicle starts to spin, it 3 The areas before intersections chains and non-metal chains.
tends to spin towards the lower and corners tend to have slippery Non-metal chains are lighter, easi-
side of the road or towards the surfaces, as many vehicles have er to carry and attach. Conversely,
direction of the tire that slipped. applied brakes at those points metal chains are heavier and more
Slowly, step on the accelerator before. difficult to attach. Yet, they are but makes correction easier. If the
pedal (don’t release the pedal) and cheaper and easier to repair if bro- vehicle gets stuck, the chains can
counter-steer to regain control. UP-HILL SLOPE ken and thus more suitable for be removed and reattached to the
3 When the vehicle starts to lose Start the climb by observing the cross-country driving. front tires for traction. Where
traction during cornering, drivers vehicles ahead and try not to stop 2 Attaching chains: Chains chains should be attached (front or
tend to overcompensate.The driv- while climbing. If you are forced to should be attached as soon as the rear tires) is a case-by-case deci-
er should be aware of this tenden- stop and can not restart,back up to snow starts falling continuously. If sion, but generally it is recom-
cy, as sometimes the vehicle the bottom of the slope and oncoming vehicles are wearing mended to use the rear tires.
regains traction suddenly and restart there. them, attach chains. In the case of
starts a sharp turn. 4WD, attach chains to the tires
DOWN-HILL SLOPE with the heavier load. On deep Other tips for cold places
BRAKE Shifting or sudden deceleration snow or for driving downhill, use
1 Test the braking for tire lock-up while going downhill should be the front tires. In pressed snows SNOW ACCUMULATION ON THE
in a safe environment. Knowing avoided as the vehicle could lose and up-hill, use the rear tires. Gen- VEHICLE
this limit helps the driver make traction.Choose a low gear and let erally speaking, attaching to the While driving, snow that sticks to
delicate maneuver under pressure the engine control the speed. front tires risks damage to the the fenders could interfere with
situations. inside of wheel-housing, axle or steering and snow on the head-
2 Even vehicles with studless tires brake hose.Regarding vehicle con- lamps could affect the beam.
or those using tire chains have trol, attaching chains to the rear Check these potential problems by
lower grip against horizontal mo- tires can increase under-steering, inspecting it from time to time.
2 Driving Techniques
TRY NOT TO BRING SNOW INTO FREEZING OF THE DOOR RADIATOR LIQUID’S QUANTITY
THE VEHICLE If you force the door to open after AND CONCENTRATION
Be careful not to bring the snow it becomes frozen,you might dam- Prevent freezing by adding LLC
inside the vehicle on shoes and age its rubber seal. Apply heat anti-freezing radiator fluid.
clothes as it could make the pedal with moderately warm water and
surface slippery or freeze the ped- wait for the door to defrost. WINDOW-WASHER FLUID
als when the vehicle is parked. cable. In an extremely cold place, Driving through snowy conditions
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