Ford Low Cab Forward (Ford year). Manual — part 41

Tires should be inspected for the following conditions. If any are present,
the tire should be removed and repaired, retreaded or scrapped as the
condition indicates.
• Any blister, bump or raised portion anywhere on the surface of the

tire tread or sidewall (other than a bump made by a repair). These
indicate the start of internal separation.

• Any cut that reaches to the belt or ply cords, or any cut that is large

enough to grow in size and depth.

• Any nail or puncturing object.
• If any stone or object is held by a tread groove and is starting to drill

into the tread base, remove the object.

Proper tire inflation, toe-in adjustment, loads, and road speeds are
important factors governing tire mileage, steering ease and
maneuverability.

Loads

Loading tires beyond their rated capacity decreases tire life
requiring more frequent replacement of tires. Overloading

creates an unsafe condition that may result in sudden air loss from a
tire failure resulting in an accident that could cause property damage,
personal injury or death.

Note: Your GAW/GVW rating is correct at the time of your vehicle
production, and reflects the exact rating of the tires specified. When
replacing tires be sure that the replacement tire load rating (listed in
pounds and kilograms on the tire sidewall) is the same or higher than
the tire that is removed. Failure to do so will adversely affect maximum
load carrying capacity. Tires with the same size specification do not
always have the same load specification.

Matching

Dual Tires: Dual tires should be matched using tires of equivalent size.
Tires which differ more than

1

⁄

4

inch (6 mm) in diameter or

3

⁄

4

inch

(19 mm) in circumference should not be mounted on the same dual
wheel assembly.

Mixing: Never mix bias and radial tires on this vehicle. Never mix
different tire sizes or constructions on the same axle. Note: Never mix
bias and radial tires on this vehicle.

Maintenance and Specifications

166

Rotation:

Rotation is always advisable:

1. If front (steering) axle tires become irregularly worn, move to rear
position.

2. In a dual assembly, reverse the position of the tires if one tire wears
much faster than its mate.

3. On the drive axle, if heel and toe wear or alternate lug wear occurs,
rotating the tires from one end of the axle to the other end of the axle
may help even out this wear.

Rotation may not advisable:

1. Front (Steering) Axle: Tires must be removed when tread is worn
to 4/32 inch (3 mm) or less. Retread or rotate worn tires to drive
position. Retreaded tires are not recommended to be used on steering
axles.

2. Rear Axles: Tires must be removed when tread is worn to 2/32 inch
(2 mm).

If rib tire is used on front axle and lug or off-road type on rear axle
positions:

1. Front (Steering) Axle: Replace tires at front wheels when tread is
worn to 4/32 inch (3 mm) or less.

2. Rear Axles: Tires must be removed when the tread is worn to 2/32
inch (2 mm) or less. Tires identified with the word “re-groovable”
molded on the sidewall can be re-grooved. A minimum of 3/32 inch
(2.5 mm) of under-tread must be left at the bottom of the grooves.

Wheel and tire balancing

Out-of-round or out-of-balance wheels or tires can cause vehicle
vibration, bounce and shimmy. Replace damaged or out-of-round wheels.
Out-of-round tires and wheel assemblies can be corrected by re-clocking
the tire relative to the wheel.

The tire and wheel assembly should then be dynamically balanced.

Wear

Radial tires can exhibit three types of normal wear patterns: 1) Even,
2) Erosion, 3) Chamfer.

Even wear is a sign that the tire is being properly used and maintained.

Maintenance and Specifications

167

Erosion wear has also been called rolling wear, channel or river wear.
Erosion wear is found more often at free rolling tires. This is an
indication that the tire is being used in a slow wearing operation. What
happens is that the belt plies are held very rigid and the tread is not
allowed to distort as it passes through the contact area. Wear will only
occur at the edge of the tread. No corrective action required. If erosion
gets to be 1/16 inch (2 mm) or more, the tire may be rotated to a drive
axle.

Chamfer or shoulder wear, with tires inflated properly, is a normal
tendency of most radial tire designs. If both inside and outside shoulders
are wearing evenly around the tire, no further action is required.
Over-inflation is not effective in correcting this effect.

Tires: Irregular Wear
If irregular wear is present, check the axle alignment, tire pressure,
wheel balancing, shock and suspension component condition, and wheel
bearing end play.

This condition not only shortens tire life, but will adversely affect the
handling of your vehicle, which is dangerous.

Rotating tires from one wheel position to another is a way often used to
even out many types of irregular wear or to avoid it altogether. Some of
the more effective tire rotation programs are:
• Steer tires that have developed some type of irregular wear pattern

can be rotated to drive axles if rib tires are being used on all wheel
positions. Applying steer tires to a drive position will often clean them
and they can be moved back to the steer axles or run out to re-tread
stage on the rear axle.

• Another rotation possibility for fleets with rib tires in all wheel

positions is to break in the new steer tires in the drive axle positions,
then move them to steer axles. This will wear away tread rubber
relatively quickly in the early life of a tire when it is most likely to
develop an unusual wear pattern.

• Drive axle tires may be placed on the other end of the same axle so

that direction of rotation is reversed. This is often helpful if a heel and
toe or alternate lug wear pattern has developed.

Irregular wear can be minimized by:
• Using the right inflation pressure for the load being carried.
• Maintaining proper front wheel alignment - especially toe-in - to

specifications.

• Maintaining proper tire and wheel balance.

Maintenance and Specifications

168

• Maintaining shock absorbers and suspension components.

Use of tire chains

Refer to chain manufacturer’s recommendation for correct tire chain
usage, installation and removal.

Tire inflation information

All tires with Steel Carcass Plies (if equipped):

This type of tire utilizes steel cords in the sidewalls. As such, they
cannot be treated like normal light truck tires. Tire service, including
adjusting the air pressure, must be performed by personnel trained,
supervised and equipped according to Federal Occupational Safety and
Health Administration (OSHA) regulations. For example, during any
procedure involving tire inflation, the technician or individual must
utilize a remote inflation device, and ensure that all persons are clear of
the trajectory area.

WARNING An inflated tire and rim can be very dangerous if
improperly used, serviced or maintained. To reduce the risk of

serious injury, never attempt to re-inflate a tire which has been run flat
or seriously under-inflated without first removing the tire from the
wheel assembly for inspection. Do not attempt to add air to tires or
replace tires or wheels without first taking precautions to protect
persons and property.

Maintenance and Specifications

169