SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
3500 Series 190 +10 140 +10 ±
2500 Series 240 +10 177 +10 ±
TIRES
DESCRIPTION
DESCRIPTION - TIRES
Tires are designed and engineered for each specific
vehicle. They provide the best overall performance
for normal operation. The ride and handling charac-
teristics match the vehicle's requirements. With
proper care they will give excellent reliability, trac-
tion, skid resistance, and tread life.
Driving habits have more effect on tire life than
any other factor. Careful drivers will obtain in most
cases, much greater mileage than severe use or care-
less drivers. A few of the driving habits which will
shorten the life of any tire are:
²Rapid acceleration
²Severe brake applications
²High speed driving
²Excessive speeds on turns
²Striking curbs and other obstacles
Radial-ply tires are more prone to irregular tread
wear. It is important to follow the tire rotation inter-
val shown in the section on Tire Rotation, (Refer to
22 - TIRES/WHEELS - STANDARD PROCEDURE).
This will help to achieve a greater tread life.
TIRE IDENTIFICATION
Tire type, size, aspect ratio and speed rating are
encoded in the letters and numbers imprinted on the
side wall of the tire. Refer to the chart to decipher
the tire identification code (Fig. 11).
Performance tires have a speed rating letter after
the aspect ratio number. The speed rating is not
always printed on the tire sidewall. These ratings
are:
²Qup to 100 mph
²Rup to 106 mph
²Sup to 112 mph
²Tup to 118 mph
²Uup to 124 mph²Hup to 130 mph
²Vup to 149 mph
²Zmore than 149 mph (consult the tire manu-
facturer for the specific speed rating)
An All Season type tire will have eitherM+S,M
&SorM±S(indicating mud and snow traction)
imprinted on the side wall.
TIRE CHAINS
Tire snow chains may be used oncertainmodels.
Refer to the Owner's Manual for more information.
DESCRIPTION - RADIAL ± PLY TIRES
Radial-ply tires improve handling, tread life and
ride quality, and decrease rolling resistance.
Fig. 11 Tire Identification
VATIRES/WHEELS 22 - 7
Radial-ply tires must always be used in sets of
four. Under no circumstances should they be used on
the front only. They may be mixed with temporary
spare tires when necessary. A maximum speed of 50
MPH is recommended while a temporary spare is in
use.
Radial-ply tires have the same load-carrying capac-
ity as other types of tires of the same size. They also
use the same recommended inflation pressures.
The use of oversized tires, either in the front or
rear of the vehicle, can cause vehicle drive train fail-
ure. This could also cause inaccurate wheel speed
signals when the vehicle is equipped with Anti-Lock
Brakes.
The use of tires from different manufactures on the
same vehicle is NOT recommended. The proper tire
pressure should be maintained on all four tires.
DESCRIPTION - TIRE PRESSURE FOR HIGH
SPEEDS
Where speed limits allow the vehicle to be driven
at high speeds, correct tire inflation pressure is very
important. For speeds up to and including 120 km/h
(75 mph), tires must be inflated to the pressures
shown on the tire placard. For continuous speeds in
excess of 120 km/h (75 mph), tires must be inflated
to the maximum pressure specified on the tire side-
wall.
Vehicles loaded to the maximum capacity should
not be driven at continuous speeds above 75 mph
(120 km/h).
For emergency vehicles that are driven at speeds
over 90 mph (144 km/h), special high speed tires
must be used. Consult tire manufacturer for correct
inflation pressure recommendations.
DESCRIPTION - REPLACEMENT TIRES
The original equipment tires provide a proper bal-
ance of many characteristics such as:
²Ride
²Noise
²Handling
²Durability
²Tread life
²Traction
²Rolling resistance
²Speed capability
It is recommended that tires equivalent to the orig-
inal equipment tires be used when replacement is
needed.
Failure to use equivalent replacement tires may
adversely affect the safety and handling of the vehi-
cle.The use of oversize tires may cause interference
with vehicle components. Under extremes of suspen-
sion and steering travel, interference with vehicle
components may cause tire damage.
WARNING: FAILURE TO EQUIP THE VEHICLE WITH
TIRES HAVING ADEQUATE SPEED CAPABILITY
CAN RESULT IN SUDDEN TIRE FAILURE.
DESCRIPTION - TIRE INFLATION PRESSURES
Under inflation will cause rapid shoulder wear, tire
flexing, and possible tire failure (Fig. 12).
Over inflation will cause rapid center wear and
loss of the tire's ability to cushion shocks (Fig. 13).
Improper inflation can cause:
²Uneven wear patterns
²Reduced tread life
²Reduced fuel economy
²Unsatisfactory ride
Fig. 12 Under Inflation Wear
1 - THIN TIRE THREAD AREAS
Fig. 13 Over Inflation Wear
1 - THIN TIRE THREAD AREA
22 - 8 TIRES/WHEELSVA
²Vehicle drift
For proper tire pressure specification refer to the
Tire Inflation Pressure Chart provided with the vehi-
cles Owners Manual. A Certification Label on the
drivers side door pillar provides the minimum tire
and rim size for the vehicle. The label also list the
cold inflation pressure for these tires at full load
operation
Tire pressures have been chosen to provide safe
operation, vehicle stability, and a smooth ride. Tire
pressure should be checked cold once a month. Tire
pressure decreases as the ambient temperature
drops. Check tire pressure frequently when ambient
temperature varies widely.
Tire inflation pressures are cold inflation pressure.
The vehicle must sit for at least 3 hours to obtain the
correct cold inflation pressure reading. Or be driven
less than one mile after sitting for 3 hours. Tire
inflation pressures may increase from 2 to 6 pounds
per square inch (psi) during operation. Do not reduce
this normal pressure build-up.
WARNING: OVER OR UNDER INFLATED TIRES CAN
AFFECT VEHICLE HANDLING AND TREAD WEAR.
THIS MAY CAUSE THE TIRE TO FAIL SUDDENLY,
RESULTING IN LOSS OF VEHICLE CONTROL.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES
A quality air pressure gauge is recommended to
check tire pressure. After checking the air pressure,
replace valve cap finger tight.
DIAGNOSIS AND TESTING - TIRE NOISE OR
VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, vibration, wheel
defects, or possibly tire imbalance.
To find out if tires are causing the noise or vibra-
tion, drive the vehicle over a smooth road at varying
speeds. Note the noise level during acceleration and
deceleration. The engine, differential and exhaust
noises will change as speed varies, while the tire
noise will usually remain constant.
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread depth is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band (Fig. 14).Tire replacement is necessary when indicators
appear in two or more grooves or if localized balding
occurs.
DIAGNOSIS AND TESTING - TIRE WEAR PAT-
TERNS
Under inflation will cause wear on the shoulders of
tire. Over inflation will cause wear at the center of
tire.
Excessive camber causes the tire to run at an
angle to the road. One side of tread is then worn
more than the other (Fig. 15).
Excessive toe-in or toe-out causes wear on the
tread edges and a feathered effect across the tread
(Fig. 15).
Fig. 14 Tread Wear Indicators
1 - TREAD ACCEPTABLE
2 - TREAD UNACCEPTABLE
3 - WEAR INDICATOR
VATIRES/WHEELS 22 - 9
will remain stationary during the repair. Misalign-
ment can cause stress in the repair areas and can
result in future failure.
VISUAL INSPECTION
Composite materials can mask the severity of an
accident. Adhesive bond lines, interior structure of
the doors, and steel structures need to be inspected
carefully to get a true damage assessment. Close
inspection may require partial removal of interior
trim or inner panels.
Identify the type of repair: Puncture or Crack -
Damage that has penetrated completely through the
panel. Damage is confined to one general area; a
panel section is not required. However, a backer
panel, open fiberglass tape, or matted material must
be bonded from behind (Fig. 7) (Fig. 6).
PANEL SURFACE PREPARATION
If a body panel has been punctured, cracked, or
crushed, the damaged area must be removed from
the panel to achieve a successful repair. All spider
web cracks leading away from a damaged area must
be stopped or removed. To stop a running crack in a
panel, drilla6mm(0.250 in.) hole at the end of the
crack farthest away from the damage. If spider web
cracks can not be stopped, the panel would require
replacement. The surfaces around the damaged area
should be stripped of paint and freed from wax andoil. Scuff surfaces around repair area with 360 grit
wet/dry sandpaper, or equivalent, to assure adhesion
of repair materials.
PATCHING PANELS
An panel that has extensive puncture type damage
can be repaired by cutting out the damaged material
(Fig. 7). Use a suitable reciprocating saw or cut off
wheel to remove the section of the panel that is dam-
aged. The piece cut out can be used as a template to
shape the new patch. It is not necessary to have
access to the back of the panel to install a patch.
Bevel edges of cutout at 20 degrees to expose a larger
bonding area on the outer side. This will allow for an
increased reinforcement areas.
PANEL PATCH FABRICATIONS
A patch can be fabricated from any rigid fiberglass
panel that has comparable contour with the repair
area. Lift gates and fenders can be used to supply
patch material. If existing material is not available
or compatible, a patch can be constructed with adhe-
sive and reinforcement mesh (dry wall tape). Perform
the following operation if required:
(1) Cover waxed paper or plastic with adhesive
backed nylon mesh (dry wall tape) larger than the
patch required (Fig. 8).
(2) Tape waxed paper or plastic sheet with mesh to
a surface that has a compatible contour to the repair
area.
(3) Apply a liberal coat of adhesive over the rein-
forcement mesh (Fig. 8). If necessary apply a second
or third coat of adhesive and mesh after firs coat has
cured. The thickness of the patch should be the same
as the repair area.
(4) After patch has cured, peel waxed paper or
plastic from the back of the patch.
Fig. 5 FIBERGLASS TAPE
Fig. 6 DAMAGE COMPONENT
1 - PUNCTURE
Fig. 7 DAMAGED PANEL CUTOUT AND PATCH
1 - CUTOUT
2 - DAMAGED BODY PANEL
3-4MM(0.160 IN.) HOLES
4 - PATCH CUT TO SIZE
VABODY 23 - 7