1991 1999 ford explorer chilton User Manual

							
TIRE ROTATION
Tires must be rotated periodically to equalize wear patterns that vary with a tires position on the vehicle. Tires
will also wear in an uneven way as the front steering/suspension system wears to the point where the
alignment should be reset.
Rotating the tires will ensure maximum life for the tires as a set, so you will not have to discard a tire early
due to wear on only part of the tread. Regular rotation is required to equalize wear.
When rotating unidirectional tires, make sure that they always roll in the same direction. This means that a
tire used on the left side of the vehicle must not be switched to the right side and vice-versa. Such tires should
only be rotated front-to-rear or rear-to-front, while always remaining on the same side of the vehicle. These
tires are marked on the sidewall as to the direction of rotation; observe the marks when reinstalling the tire(s).
Common tire rotation patterns for 4 and 5-wheel rotationsClick to enlarge
Some styled or mag wheels may have different offsets front to rear. In these cases, the rear wheels must not
be used up front and vice-versa. Furthermore, if these wheels are equipped with unidirectional tires, they
cannot be rotated unless the tire is remounted for the proper direction of rotation.
The compact or space-saver spare is strictly for emergency use. It must never be included in the tire
rotation or placed on the vehicle for everyday use.
TIRE DESIGN
For maximum satisfaction, tires should be used in sets of four. Mixing of different brands or types (radial,
bias-belted, fiberglass belted) should be avoided. In most cases, the vehicle manufacturer has designated a
type of tire on which the vehicle will perform best. Your first choice when replacing tires should be to use the
same type of tire that the manufacturer recommends.
When radial tires are used, tire sizes and wheel diameters should be selected to maintain ground clearance and
tire load capacity equivalent to the original specified tire. Radial tires should always be used in sets of four. HOW TO USE THIS BOOK
TIRE ROTATION 97 
						

							P-Metric tire coding
Click to enlarge
CAUTION
Radial tires should never be used on only the front axle.
When selecting tires, pay attention to the original size as marked on the tire. Most tires are described using an
industry size code sometimes referred to as P-Metric. This allows the exact identification of the tire
specifications, regardless of the manufacturer. If selecting a different tire size or brand, remember to check the
installed tire for any sign of interference with the body or suspension while the vehicle is stopping, turning
sharply or heavily loaded.
Snow Tires
Good radial tires can produce a big advantage in slippery weather, but in snow, a street radial tire does not
have sufficient tread to provide traction and control. The small grooves of a street tire quickly pack with snow
and the tire behaves like a billiard ball on a marble floor. The more open, chunky tread of a snow tire will
self-clean as the tire turns, providing much better grip on snowy surfaces.
To satisfy municipalities requiring snow tires during weather emergencies, most snow tires carry either an M
+ S designation after the tire size stamped on the sidewall, or the designation all-season. In general, no
change in tire size is necessary when buying snow tires.
Most manufacturers strongly recommend the use of 4 snow tires on their vehicles for reasons of stability. If
snow tires are fitted only to the drive wheels, the opposite end of the vehicle may become very unstable when
braking or turning on slippery surfaces. This instability can lead to unpleasant endings if the driver cant HOW TO USE THIS BOOK
98 TIRE DESIGN 
						

							
counteract the slide in time.
Note that snow tires, whether 2 or 4, will affect vehicle handling in all non-snow situations. The stiffer,
heavier snow tires will noticeably change the turning and braking characteristics of the vehicle. Once the
snow tires are installed, you must re-learn the behavior of the vehicle and drive accordingly.
Consider buying extra wheels on which to mount the snow tires. Once done, the snow wheels can be
installed and removed as needed. This eliminates the potential damage to tires or wheels from seasonal
removal and installation. Even if your vehicle has styled wheels, see if inexpensive steel wheels are
available. Although the look of the vehicle will change, the expensive wheels will be protected from salt,
curb hits and pothole damage.
TIRE STORAGE
If they are mounted on wheels, store the tires at proper inflation pressure. All tires should be kept in a cool,
dry place. If they are stored in the garage or basement, do not let them stand on a concrete floor; set them on
strips of wood, a mat or a large stack of newspaper. Keeping them away from direct moisture is of paramount
importance. Tires should not be stored upright, but in a flat position.
INFLATION & INSPECTION
The importance of proper tire inflation cannot be overemphasized. A tire employs air as part of its structure. It
is designed around the supporting strength of the air at a specified pressure. For this reason, improper inflation
drastically reduces the tires ability to perform as intended. A tire will lose some air in day-to-day use; having
to add a few pounds of air periodically is not necessarily a sign of a leaking tire.
Two items should be a permanent fixture in every glove compartment: an accurate tire pressure gauge and a
tread depth gauge. Check the tire pressure (including the spare) regularly with a pocket type gauge. Too often,
the gauge on the end of the air hose at your corner garage is not accurate because it suffers too much abuse.
Always check tire pressure when the tires are cold, as pressure increases with temperature. If you must move
the vehicle to check the tire inflation, do not drive more than a mile before checking. A cold tire is generally
one that has not been driven for more than three hours.
Tires with deep cuts, or cuts which bulge, should be replaced immediately HOW TO USE THIS BOOK
TIRE STORAGE 99 
						

							Radial tires have a characteristic sidewall bulge; dont try to measure pressure by looking at the
tire. Use a quality air pressure gauge
Click to enlarge
Common tire wear patterns and causes Click to enlarge
A plate or sticker is normally provided somewhere in the vehicle (door post, hood, tailgate or trunk lid) which
shows the proper pressure for the tires. Never counteract excessive pressure build-up by bleeding off air
pressure (letting some air out). This will cause the tire to run hotter and wear quicker.
CAUTION
Never exceed the maximum tire pressure embossed on the tire! This is the pressure to be used when the tire is
at maximum loading, but it is rarely the correct pressure for everyday driving. Consult the owners manual or
the tire pressure sticker for the correct tire pressure.
Once youve maintained the correct tire pressures for several weeks, youll be familiar with the vehicles
braking and handling personality. Slight adjustments in tire pressures can fine-tune these characteristics, but
never change the cold pressure specification by more than 2 psi. A slightly softer tire pressure will give a
softer ride but also yield lower fuel mileage. A slightly harder tire will give crisper dry road handling but can
cause skidding on wet surfaces. Unless youre fully attuned to the vehicle, stick to the recommended inflation
pressures.
All automotive tires have built-in tread wear indicator bars that show up as  1
/2  in. (13mm) wide smooth bands
across the tire when  1
/16  in. (1.5mm) of tread remains. The appearance of tread wear indicators means that the HOW TO USE THIS BOOK
100 INFLATION & INSPECTION 
						

							
tires should be replaced. In fact, many states have laws prohibiting the use of tires with less than this amount
of tread.
Tread wear indicators will appear when the tire is worn
Accurate tread depth indicators are inexpensive and handy
You can check your own tread depth with an inexpensive gauge or by using a Lincoln head penny. Slip the
Lincoln penny (with Lincolns head upside-down) into several tread grooves. If you can see the top of
Lincolns head in 2 adjacent grooves, the tire has less than  1
/16  in. (1.5mm) tread left and should be replaced.
You can measure snow tires in the same manner by using the tails side of the Lincoln penny. If you can see
the top of the Lincoln memorial, its time to replace the snow tire(s). HOW TO USE THIS BOOK
INFLATION & INSPECTION 101 
						

							A penny works well for a quick check of tread depth
Chilton® Automotive Information Systems. © 2004 Thomson Delmar Learning. HOW TO USE THIS BOOK
102 INFLATION & INSPECTION 
						

							
FLUIDS AND LUBRICANTS
Fluid Disposal
Used fluids such as engine oil, transmission fluid, antifreeze and brake fluid are hazardous wastes and must be
disposed of properly. Before draining any fluids, consult with the local authorities; in many areas, waste oil,
etc. is being accepted as part of recycling programs. A number of service stations and auto parts stores are
also accepting waste fluids for recycling.
Be sure of the recycling centers policies before draining any fluids, as many will not accept different fluids
that have been mixed together, such as oil and antifreeze.
Oil and Fuel Recommendations
ENGINE OIL
Engine oil viscosity chartClick to enlarge
The recommended oil viscosities for sustained temperatures ranging from below 0°F (-18°C) to above 32°F
(0°C) are listed in this Section. They are broken down into multi-viscosity and single viscosities.
Multi-viscosity oils are recommended because of their wider range of acceptable temperatures and driving
conditions.
Ford recommends that SAE 5W-30 viscosity engine oil should be used for all climate conditions,
however, SAE 10W-30 is acceptable for vehicles operated in moderate to hot climates.
When adding oil to the crankcase or changing the oil or filter, it is important that oil of an equal quality to
original equipment be used in your truck. The use of inferior oils may void the warranty, damage your engine,
or both.
The SAE (Society of Automotive Engineers) grade number of oil indicates the viscosity of the oil (its ability
to lubricate at a given temperature). The lower the SAE number, the lighter the oil; the lower the viscosity, the
easier it is to crank the engine in cold weather but the less the oil will lubricate and protect the engine in high
temperatures. This number is marked on every oil container.
FLUIDS AND LUBRICANTS 103 
						

							
Oil viscosities should be chosen from those oils recommended for the lowest anticipated temperatures during
the oil change interval. Due to the need for an oil that embodies both good lubrication at high temperatures
and easy cranking in cold weather, multigrade oils have been developed. Basically, a multigrade oil is thinner
at low temperatures and thicker at high temperatures. For example, a 10W-40 oil (the W stands for winter)
exhibits the characteristics of a 10 weight (SAE 10) oil when the truck is first started and the oil is cold. Its
lighter weight allows it to travel to the lubricating surfaces quicker and offer less resistance to starter motor
cranking than, say, a straight 30 weight (SAE 30) oil. But after the engine reaches operating temperature, the
10W-40 oil begins acting like straight 40 weight (SAE 40) oil, its heavier weight providing greater
lubrication with less chance of foaming than a straight 30 weight oil.
Look for the API oil identification label when choosing your engine oil
The API (American Petroleum Institute) designations, also found on the oil container, indicates the
classification of engine oil used under certain given operating conditions. Only oils designated for use Service
SG heavy duty detergent should be used in your truck. Oils of the SG type perform may functions inside the
engine besides their basic lubrication. Through a balanced system of metallic detergents and polymeric
dispersants, the oil prevents high and low temperature deposits and also keeps sludge and dirt particles in
suspension. Acids, particularly sulfuric acid, as well as other by-products of engine combustion are
neutralized by the oil. If these acids are allowed to concentrate, they can cause corrosion and rapid wear of the
internal engine parts.
CAUTION
Non-detergent motor oils or straight mineral oils should not be used in your Ford gasoline engine.
Synthetic Oil
There are many excellent synthetic and fuel-efficient oils currently available that can provide better gas
mileage, longer service life, and in some cases better engine protection. These benefits do not come without a
few hitches, however; the main one being the price of synthetic oils, which is three or four times the price per
quart of conventional oil.
Synthetic oil is not for every truck and every type of driving, so you should consider your engines condition
and your type of driving. Also, check your trucks warranty conditions regarding the use of synthetic oils.
High mileage engines are the wrong candidates for synthetic oil. Older engines with wear have a problem with
synthetics: they use (consume during operation) more oil as they age. Slippery synthetic oils get past these
worn parts easily. If your engine is using conventional oil, it will use synthetics much faster. Also, if your HOW TO USE THIS BOOK
104 ENGINE OIL 
						

							Remove the engine oil dipstick to check the level
Wipe the dipstick with a clean, lint-free rag and reinsert it. Be sure to insert it all the way.
2. 
Pull out the dipstick and note the oil level. It should be between the FULL(MAX) mark and the
ADD(MIN) mark.
3. 
The level should read below the FULL but above the ADD mark
If the level is below the lower mark, replace the dipstick and add fresh oil to bring the level within the
proper range. Do not overfill.
4.  HOW TO USE THIS BOOK
106 OIL LEVEL CHECK