Radial Tire Conditions Analysis Guide

Radial Tire Conditions Analysis Guide
RADIAL TIRE
CONDITIONS ANALYSIS
GUIDE
A Comprehensive
Review of Tread Wear
and
Tire Conditions
RADIAL TIRE
CONDITIONS
ANALYSIS
GUIDE
A Comprehensive
Review of Tread Wear
And Tire Conditions
© Copyright 1994 The Maintenance Council
Printed in U.S.A.
Replaces 1984 Out of Service Tire Analysis Guide
and Radial Tire Wear Conditions and Causes
The procedures contained herein reflect the consensus of the members of The
Maintenance Council (TMC) on those items and methods that have delivered
the best performance record based on the experience of those present at the
meetings of the Council. The procedures contained herein are not exclusive.
TMC cannot possibly know, evaluate or advise the transportation industry of
all conceivable ways in which a procedure may be undertaken or of the possible consequences of each such practice. Other practices or methods may be
as good or better depending upon the particular circumstances involved.
Every carrier who uses the procedures contained herein must first satisfy itself
thoroughly that neither the safety of its employees or agents nor the safety or
usefulness of any products will be jeopardized by any method selected.
The following procedures are not intended nor should they be construed as an
endorsement of any particular person, organization or product.
For information on obtaining additional copies of this guide, contact
The Maintenance Council
2200 Mill Road
Alexandria, VA 22314
(703) 838-1763
Or Call American Trucking Associations Customer Service
(800) ATA-LINE
Order Item # T0121 (TMC/ATA Members) or T0126 (Non-members)
II
We would like to thank the following companies
who participated in the development of this guide
by donating their expertise and photographs
American Retreaders Association
Bandag, Inc.
Acknowledgment
Bridgestone/Firestone, Inc.
Cooper Tire and Rubber Co.
General Tire, Inc.
Goodyear Tire & Rubber Co.
Hankook Tire America Corp.
Hawkinson Companies
Hercules Tire and Rubber Co.
KLLM, Inc.
Kumho USA, Inc.
Michelin Tire Corp.
Rema Tip Top/North America, Inc.
Roadway Tire Co.
Sumitomo Tire
Tech International
Toyo Tire (U.S.A.) Corp.
Truflex/Pang Rubber Co.
III
Table Of Contents
Introduction
Glossary
VIII
XIII
I. New Tire (Original Tread) and Casing Conditions
1
A. Bead Area
Torn Beads
Kinked/Distorted Beads
Bead Deformation
Burned Beads
Reinforce/Chafer Separation
Petro/Lubricant Damage
Bead Damage From Curbing
Bead Area Flow Crack
3
4
5
6
7
8
9
10
11
B. Sidewall Area
Spread/Damaged Cord
Cuts and Snags
Sidewall Separation
Chain Damage
Vehicle/Equipment Damage
Damage Induced Sidewall Separation
Sidewall Abrasion/Scuff Damage
Weathering
Impact Break
Branding Damage
Diagonal Cracking
Petroleum Product Damage
Forklift Damage
Circumferential Fatigue Rupture (Zipper)
Open Sidewall Splice
Sidewall Bumps (Blisters)
Sidewall Penetration
Radial Split
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
C. Crown Area
Penetrations and Road Hazards
Vehicle Damage
Forklift Damage/Cuts and Snags
Belt Lift/Separation
Tread Lift/Separation
Brake Skid Damage
Tread /Chunking
Lug Base Cracking
Wild Wire
Impact Breaks
33
34
35
36
37
38
39
40
41
42
43
IV
Table Of Contents
Chipping/Flaking/Chunking Tread
Stone Drilling
Regrooving Damage
Dynamometer Type Damage
Chemical Damage
Excessive Wear
Rib Tearing
Defense Groove Tearing
Groove Cracking
Spin Damage
44
45
46
47
48
49
50
51
52
53
D. Tire Interior
Penetrating Objects
Open Inner Liner Splice
Inner Liner Bubbles, Blisters, & Separations
Inner Liner Cracking
Pulled/Loose Cords
Tearing, Mount/Dismount Damage
Foreign Object Inner Liner Damage in Tubeless Tire
Run Flat
Pinch Stock
Impact Break
55
56
57
58
59
60
61
62
63
64
65
E. Any Area
Run Flat
Electrical Discharge
67
68
69
II. Retread and Repair Conditions
71
Introduction to Retread Conditions
72
A. Holes and Injuries
Bad Spot Repair
Spot Repair Should Be A Section
Improper Nail Hole Repair
Improperly Aligned Repair
Unfilled Nail Hole Repair
Bridged Repair
On The Wheel Repair
Bad Bead Repair
Failed Repair -- Injury Not Removed
Bias Repair in Radial Tire
73
74
75
76
77
78
79
80
81
82
83
V
Table Of Contents
II. Retread and Repair Conditions (Continued)
B. Missing/Loose Tread
Bond Line Porosity
Tread Separation
Tread Chunking At Splice
Tread Separation - Repair Related
Belt Separation - Repair Related
Missed Puncture
Tread Edge Lifting
85
86
87
88
89
90
91
92
C. Cracks
Failed Inner Liner Repair
Lug Base Cracking
Improper Tread Width
Open Tread Splice
93
94
95
96
97
D. Bulges/Depressions
Skive Failure
Repair Related Bulge
Buckled Tread
99
100
101
102
E. Miscellaneous
Delamination
Tread Surface Porosity
Wing Lift
Failed Repair From Underinflation
103
104
105
106
107
VI
Table Of Contents
III. Radial Tire Wear Conditions and Causes
109
Introduction to Radial Tire Wear Conditions and Causes
110
Section A: Steer Axle Tires
Shoulder Step/Chamfer Wear
Full Shoulder Wear
Feather Wear
Erosion/River/Channel Wear
Cupping/Scallop Wear
One Sided Wear
Diagonal Wear
Eccentric/Out-Of-Round Wear
Overall Fast Wear
Rib Depression/Punch Wear
Erratic Depression Wear
111
112
113
114
115
116
117
118
119
120
121
122
Section B: Drive Axle Tires
Shoulder Step/Chamfer Wear
Heel/Toe Wear
Alternate Lug Wear
Brake Skid/Flat Spot Wear
Overall Fast Wear
123
124
125
126
127
128
Section C: Trailer Axle Tires
Brake Skid/Flat Spot Wear
Diagonal Wear
Multiple Flat Spotting Wear
Rapid Shoulder Wear - One Shoulder
Shoulder Scrubbing/Scuffing
Rapid Shoulder Wear - Both Shoulders
Erratic Depression Wear
One-Sided Wear
Erosion/River/Channel Wear
Rib Depression/Punch Wear
129
130
131
132
133
134
135
136
137
138
139
VII
Introduction
VIII
Introduction
Determining the causes of tires placed out of service is of vital importance to the fleet operator because of the substantial investment that tires represent. To protect your investment in tires, it is
necessary to know what caused each tire's demise. This publication will lead to cost savings through
providing guidance and help in the following areas:
1.
2.
3.
4.
Eliminating causes of failures if possible.
Retreading and repairing tires and placing them back into service.
Presenting tires for warranty credit when applicable.
Improving tire maintenance and tire selection if necessary.
Tire grading should be done prior to the tire being placed in a “scrap pile.” After a tire has been
dismounted from the rim and before it is rolled out the tire shop door, the tire should be inspected with
the following questions in mind:
1.
2.
3.
4.
5.
Is the tire serviceable?
Is it repairable or retreadable?
Could it be used in a limited service operation?
Should the tire be presented to the original manufacturer or retreader for warranty?
If none of the above apply, is it strictly junk?
These questions must be answered before the tire is placed in the scrap pile since the tire may lose its
usefulness to rust while waiting in the pile to be graded. Any usable tire should be stored in a dry
covered area.
Once it is determined that a tire should be scrapped, the scrap pile itself should be organized. Instead
of piling tires randomly, arrange them in lines, leaning one against the other. One line should be
designated for originals, one for 1st caps, one for 2nd caps, etc. Bias tires should be separated from
radials. An organized scrap pile will allow you to make generalized conclusions at a glance in regards
to failed tires; i.e.,
1. If a large percentage of tires fail due to a certain operational condition, it may be that the
tire is not suitable for the service application.
2. If a large percentage of failed tires are of one brand when several makes of tires are used, it
may be that you have a problem with that manufacturer's tires.
While some deductions can be made simply by looking at an organized scrap pile, more exact conclusions can be derived regarding tire performance when tire records are maintained. Accurate and
simple records which include causes of failure, cap numbers, tread depths, etc. are extremely important and helpful when purchasing decisions must be made.
IX
Tire Inspections
Remove all foreign objects and water from the tire and place on a spreader in a well-lighted area. For
inspection purposes, the tire can be divided into seven areas:
1.
2.
3.
4.
5.
6.
7.
Tread or Crown Area.
Upper Sidewall and Shoulder Area on DOT side.
Upper Sidewall and Shoulder Area on non-DOT side.
Lower Sidewall and Bead Area on DOT side.
Lower Sidewall and Bead Area on non-DOT side.
Interior on DOT side.
Interior on non-DOT side.
For DOT explanation, see TMC Recommended Practice 210A; also see Glossary, page XIII.
Begin by inspecting the tread area. Look for punctures, cuts, foreign objects and any distortion in the
tread. Move to the upper and lower sidewalls of the DOT side and then the non-DOT side of the tire.
Inspect these areas for separation between casing components. This is usually denoted by cracks or
bulges, damage to the bead and bead wires, deterioration of rubber caused by oil and grease, weather
checking, cuts and penetrations. Then examine both sides of the interior looking for wrinkling or
corrugations in the inner liner caused by running flat or underinflated, blisters or lumps, cracks and
looseness. Mark all damage, punctures, and separations with a paint stick as you find them. Rotate
the tire as necessary for thorough inspections. Use a probe to determine the origin and extent of
damage. Inspect the complete tire prior to determining the cause of failure (i.e., often a separation in a
tire sidewall may be caused by a nail hole puncture in the tread or a failed repair that would only be
noticed by inspecting the interior of the tire). It is possible for a tire to have more than one out-ofservice condition. On the exterior of the tire, mark the final disposition based on your inspection;; for
example, repair, retread, scrap, etc.
The following is a radial tire section with definitions of its various components. Understanding the
construction of the tire will make failure analysis easier.
X
Typical Radial Tire Cross Section
Cross-Sectional View of Typical Tire
(1) Tread - This rubber provides the interface between the tire structure and the road. Primary
purpose is to provide traction and wear.
(2) Belt - Belt plies, especially steel, provide strength to the tire, stabilize the tread, and protect the air
chamber from punctures.
(3) Radial Ply - The radial ply, together with the belt plies, contains the air pressure of the tire.
The ply transmits all load, braking, and steering forces between the wheel and the tire tread.
(4) Sidewall - The sidewall rubber is specially compounded to withstand flexing and weathering
while providing protection for the radial ply.
(5) Liner - A layer of rubber in tubeless tires specially compounded for resistance to air diffusion.
The liner in the tubeless tire replaces the innertube of the tube-type tire.
(6) Apexes - Rubber pieces with selected characteristics are used to fill in the bead and lower
sidewall area and provide a smooth transition from the stiff bead area to the flexible sidewall.
(7) Bead Reinforcement - A ply laid over the radial ply turnup outside of the bead that reinforces
and stabilizes the bead-to-sidewall transition zone.
(8) GG Ring - Used as a reference for proper seating of the bead area on the rim.
(9) Bead Bundle - Made of continuous high-tensile wire wound to form a high-strength unit, the
bead bundle is the anchor foundation of the casing which maintains the required tire diameter
on the rim.
XI
The following photographs and explanations depict common tire failures and their causes. This guide
is designed to be a reference source and a training aid, and to assist users in tire grading. It advises
users when it may be necessary to consult with a specialist (original manufacturer or retreader) for
final determination of a tire's cause of failure. This guide is not designed to be the sole basis on which
to base tire or retread warranty claims.
This guide is divided into two sections. The first deals with conditions found in tubeless radial tire
casings and in original tires. Casing conditions that may be exhibited by retreaded tires can also be
found in this section. The second section addresses conditions found in the tread area of retreaded and
repaired tires.
Tubeless
XII
Glossary
Bead Chafing - Functional wear of the bead against the rim.
Bead Reinforcement - A fabric or wire ply laid over the radial ply turnup outside of the bead and
under the rubber chafer that stabilizes the bead-to-sidewall transition zone.
Bead Seat - Area where bead fits the rim.
Bead Seating - Positioning of the bead on the rim.
Bead Toe - That part of the bead which faces the inside portion of the tire.
Belt Package - Belt plies which provide strength to the tire and stabilize the tread.
Bond Line - See Buff Line.
Bonding Materials - Cushion and cement used to bond tread or repair unit to the casing.
Buff Line - The dividing line in the cross section of a tire between the buffed surface of the original tire
and the new retread rubber.
Casing - The tire structure excluding tread rubber or design.
Casing Integrity - The quality and soundness of the tire structure.
Casing Preparation - Procedures performed to prepare the casing for retreading which include
buffing, skiving, debelting, rebelting, cementing and build up.
Chassis Dynamometer - An instrument used to measure engine power involving rotating the vehicle
tires on steel rollers.
Circumferential Direction - 360˚ around the tire.
Cords - The strands of wire or fabric that form the plies and belts in a tire.
Cure - The process of vulcanization of rubber by applying heat and pressure over a period of time.
Cushion - A tacky natural rubber compound used for adhesion, undertread repair, and build up.
Cushion Migration - The shifting of the tread bonding material during vulcanization which results in
a spot of tread uncured.
Delamination - The separation of layers of rubber.
DOT Number - U.S. Department of Transportation identification number.
Dual Position - A wheel position on a vehicle where two tires and wheels are mated to carry the load.
Flow Crack - The separation of rubber compound.
Full Cap - Application of new tread rubber to include not only the tread area but also the shoulder area.
The finished retread will look like a new tire.
Inner Liner - The layer or layers of rubber laminated to the inside of a tubeless tire to contain the
inflation pressure.
XIII
Glossary
Inner Liner Splice - The overlap of inner liner material inside the tire.
Liner - See Inner Liner.
Localized Area - Isolated area; not extending throughout tire.
Lugs (Tread Lugs) - The raised block elements in the tread design.
Mold - Equipment in which a new tire is cured or equipment in which new tread is cured to a worn tire.
Mold Lubricant - Material used as a mold release to facilitate removal of the tire from the mold after
curing.
Ply - A layer of rubber coated parallel cords.
Porosity - A rubber condition which exhibits many small pores — usually the result of lack of heat or
pressure during the curing process.
Precure Tread - Tread which is vulcanized with the tread configuration molded into it prior to being
placed on the buffed casing.
Pressure Differential - The difference in pressure on the outside of the tire and in the inside of the tire
as the tread is vulcanized.
Radial Direction - From bead to bead.
Rebelt(ing) - The installation of a new fabric or steel belt in a casing after the original belt has been
removed due to excessive damage.
Repair Plug - The rubber material that fills the cavity of an injury in a tire.
Repair Unit - The reinforcing material used to strengthen the area around an injury in a tire.
Retreaded Tire - A casing to which a new tread has been cured to extend the usable life of the tire.
Ribs ( Tread Ribs) - Continuous circumferential tread elements.
Shoulder Area - General area where the sidewall meets the tread.
Spread Axles - Tandem axles which are spaced far apart to carry heavy loads.
Top Cap - Only the top or tread area is buffed and a tread rubber with abrupt shoulders is applied.
Tread Grooves - Space between two adjacent tread ribs and/or lugs.
Tread Splice - The junction of tread ends.
Undertread - The rubber between the base of the tread groove and the top belt.
Weathering - Fine hairline cracks in the sidewall surface of the tire caused by oxidation and other
atmospheric effects.
Wicking - A capillary action of air escapement from the tire casing through the use of a piece of cord.
XIV
Section I:
New Tire
(Original Tread) and
Casing Conditions
1
A. Bead Area
3
CASING CONDITIONS -- BEAD AREA
CASING
CONDITIONS
BEAD
Torn Beads
APPEARANCE
Bead toe rubber is torn or cut exposing the wire or fabric.
PROBABLE CAUSE(S) Poor mounting/demounting techniques with tire tools and/or poor
lubrication, forklift damage and poor tire handling procedures.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
If no rust on the wire is evident, repair and return to service. If wire is rusty, gouged,
kinked or broken, loose or separated, contact your tire supplier/retreader to determine
repairability; otherwise, scrap tire.
None
Review mounting/demounting procedures and tire tools. Ensure the tire beads are well
lubricated. Also check new tire handling procedures.
4
Local areas of distortion in the bead seat area.
APPEARANCE
PROBABLE CAUSE(S) Improper use of tools, or incorrect techniques used when mounting the
tire; shipping/handling damage.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Scrap tire.
None
Review mounting/dismounting procedures and tire tools.
Ensure the tire beads are lubricated.
5
BEAD
Kinked/Distorted Beads
BEAD
Bead Deformation
APPEARANCE
Circumferential indentation of the bead area on the tire
PROBABLE CAUSE(S)
Rusty rims, improper bead/rim lubrication, and bent or damaged rims
which result in improper bead seating. Excessive heat in the bead
area.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If wires are visible, scrap the tire. If only the rubber is distorted, return to service on
other than the steer axle.
None
Review mounting/demounting procedures and the use of tire tools. Ensure the tire’s
beads are well lubricated.
6
APPEARANCE
Rough, brittle, distorted and/or discolored hard surface in the bead
area.
PROBABLE CAUSE(S)
Excessive heat exposure caused by frequent hard braking; improperly
adjusted brakes; faulty braking system; insufficient air flow around
the brakes.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Scrap tire.
None
Determine the source of excessive heat and correct the braking condition.
7
BEAD
Burned Beads
BEAD
Reinforce/Chafer Separation
APPEARANCE
Circumferential cracks above bead flange area with cord material
exposed.
PROBABLE CAUSE(S)
Improper bead seating, improper rim size, overload condition,
underinflation, impact or possible manufacturing condition.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Remove from service and consult tire manufacturer.
None
Ensure proper rim sizes, mounting procedures and inflation pressures are utilized.
8
Rubber exhibits blistering, swelling, or spongy condition in the bead
area. In later stages the bead may appear dry and brittle. Petroleum
odor may be evident.
APPEARANCE
PROBABLE CAUSE(S)
Use of petroleum-based products such as a lubricant, i.e., oil, diesel
fuel and antifreeze.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Scrap tire.
None
Use of proper non-petroleum-based tire lubricants.
9
BEAD
Petro/Lubricant Damage
BEAD
Bead Damage from Curbing
APPEARANCE
Localized rippling or waviness in the bead flange area with no
exposed cord.
PROBABLE CAUSE(S)
Curbing.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Return tire to service.
None
Review driving procedures.
10
APPEARANCE
Circumferential crack above the bead with no wire exposed.
PROBABLE CAUSE(S)
Improper rubber flow during the manufacturing process.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove from service and contact the tire manufacturer.
VEHICLE
None
OPERATIONS
None
11
BEAD
Bead Area Flow Crack
B. Sidewall Area
CASING CONDITIONS -- SIDEWALL AREA
CASING
CONDITIONS
SIDEWALL
Spread/Damaged Cord
APPEARANCE
Radial, pencil shaped bulge in the sidewall of a radial tire.
PROBABLE CAUSE(S)
Wider than normal wire spacing. A tire with a repair may show this condition soon after being repaired, or the condition may arise somewhere along
a body ply that has been damaged — not necessarily in the repair area.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
ACTION
Determine the cause of the bulge. Repaired tires can often be returned to service on dual
positions unless the bulge height exceeds 3/8" when inflated. If the cause of the bulge is
not a repair or damage, contact the tire manufacturer.
None
OPERATIONS
14
APPEARANCE
Scrapes, gouges or cuts in the sidewall.
PROBABLE CAUSE(S)
Road hazard, curbing, equipment damage, wash rack rails, pit rails,
vandalism, etc.
SIDEWALL
Cuts And Snags
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
If damage has not exposed ply cords, tire may be run out on dual positions. If the cords
are visible, repair the tire if damage to the cords is within repair limits and return to
service; otherwise scrap tire.
Ensure the tire does not come in contact with vehicle hardware.
If similar damage occurs on several tires, investigate vehicle operations to determine the
cause of the damage.
15
SIDEWALL
Sidewall Separation
APPEARANCE
PROBABLE CAUSE(S)
Irregular shaped bulge in mid/upper sidewall area; may progress to
complete separation of sidewall rubber from the casing exposing the ply
cords. No repairs, breaks or punctures in the casing are evident.
Loss of adhesion between the sidewall rubber and the body ply.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove the tire from service and contact your tire manufacturer.
VEHICLE
None
OPERATIONS
None
16
APPEARANCE
Numerous pock marks around the tire on the mid to upper sidewall
and crown area.
PROBABLE CAUSE(S)
Chain abrasion often due to loose or improperly sized chains or
extended chain use on dry surfaces.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
Run out the tire on a dual position unless damage extends to the ply cord. If ply
cords are visible, consult your tire repair facility for the possibility of repair.
None
Select the proper chain size. Correct the installation procedures and enforce
chain removal when conditions warrant.
17
SIDEWALL
Chain Damage
SIDEWALL
Vehicle/Equipment Damage
APPEARANCE
Uniform scuffing or cutting on some major portion of the tire's outer
surface, often extending 360˚.
PROBABLE CAUSE(S) Contact with vehicle hardware, such as loose U-bolts, slipped spring clips,
restraining bolts, loose fenders, flap hangers and trailer wheel house
molding, etc. Can also be caused by objects trapped between the duals.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Return the tire to service on a dual position unless abrasion extends to the ply cords.
If the cords are exposed, consult your tire repair facility for the possibility of repair.
Analyze cause of the condition and correct.
None
18
Irregular shaped bulge in the mid/upper sidewall area; may progress to
complete separation of the sidewall rubber from the casing, exposing the ply
cords. Breaks in the liner, a puncture or damage to the casing is evident.
APPEARANCE
PROBABLE CAUSE(S) A puncture, impact, inner liner damage or bead damage.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Scrap tire.
None
Determine the cause and take appropriate corrective action.
19
SIDEWALL
Damage Induced Sidewall Separation
SIDEWALL
Sidewall Abrasion/Scuff Damage
APPEARANCE
Abrasion on large areas of the sidewall, often 360˚ around the tire.
PROBABLE CAUSE(S)
Rubbing against curb or guide rails. Most often seen in city delivery
service.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
If the cords are exposed, scrap tire. Otherwise, the tire can be returned to service. If
abrasion appearance is objectionable, mount the scuffed side away from the curb.
None
Review driving procedures.
20
APPEARANCE
Numerous tiny cracks in the rubber surface, most often 360˚ around
the tire.
PROBABLE CAUSE(S)
Rubber surface exposure to environmental elements. Aggravated by
long periods of parking and high concentrations of ozone.
SIDEWALL
Weathering
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
All tires may eventually exhibit this condition in late service-life stage. Tires can
be run out on the steer axle if weathering is minor; on dual positions if weathering
is moderate. Severe weathering may require removal from service.
None
Weather protection materials compounded into the tire are more effective when the
tire is exercised. Therefore, minimize parked vehicle time. Consult your tire
manufacturer if long periods of parking are expected.
21
SIDEWALL
Impact Break
APPEARANCE
Break in the sidewall through the casing. This condition will usually
deteriorate quickly to a radial runflat appearance.
PROBABLE CAUSE(S)
Caused by a sudden impact with a road hazard or a chuck hole.
Aggravated by overinflation.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your tire repair facility for the possibility of repair or scrap tire.
None
Review driving and maintenance procedures.
22
APPEARANCE
Stress cracks extending from the characters branded into the tire after
manufacture.
PROBABLE CAUSE(S)
Caused by branding too deep, in the wrong location on the tire
sidewall, at too high a temperature, or at a sharp angle.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
Tires with hairline cracks can be returned to service. Depending upon crack
severity and location, consult your tire manufacturer; if cords are exposed, scrap
tire. Otherwise consult your tire repair facility for the possibility of repair.
None
Review the tire manufacturer's branding recommendations.
23
SIDEWALL
Branding Damage
SIDEWALL
Diagonal Cracking
APPEARANCE
Diagonal crack or cracks in the upper sidewall area of tires on drive
and trailer axles.
PROBABLE CAUSE(S)
Frequently can be a result of torque transfer. Aggravated by
underflation. This condition should not be confused with cut(s) from
sharp curb edges, road hazards, etc.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove from service and consult your tire manufacturer.
VEHICLE
None
OPERATIONS
None
24
APPEARANCE
Sidewalls appear swollen, soft and spongy. In extreme cases,
sidewalls may be undulated or distorted. Petroleum odor may be
evident.
PROBABLE CAUSE(S)
Oil, diesel fuel, antifreeze or chemical contamination.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If contamination is slight, return tire to service. If there is a difference in stiffness or distortion in one sidewall when compared with the other, scrap tire.
Check vehicle for fluid leaks.
Take special precautions during fueling to avoid spills
25
SIDEWALL
Petroleum Product Damage
SIDEWALL
Forklift Damage
APPEARANCE
Cut similar to impact damage on a brand new tire.
PROBABLE CAUSE(S)
Caused during shipping and handling by lift truck forks.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Do not place in service. Determine responsibility for the damage.
None
Inspect tire upon receipt.
26
APPEARANCE
A circumferential break in the mid to upper sidewall exposing an
even line of broken cords.
PROBABLE CAUSE(S)
Severe underinflation which produces casing cord fatigue, often a
result of a puncture.
SIDEWALL
Circumferential Fatigue Rupture (Zipper)
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Scrap tire.
None
Routinely inspect all tires with inflation pressures 20% lower than your fleet's inflation
standard; thoroughly inspect all tires prior to repair and retreading; always use a safety cage
during inflation. Consult your tire or retread supplier for proper inspection procedures.
27
SIDEWALL
Open Sidewall Splice
APPEARANCE
Regular smooth opening of the top layer of sidewall rubber that may appear
radially or diagonally. Appearance is similar to a cut, however, the opening
extends at a sharp angle into the sidewall rubber. No cords are exposed.
PROBABLE CAUSE(S) Manufacturing process.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove the tire from service. Consult your tire manufacturer.
VEHICLE
None
OPERATIONS
None
28
Small, raised, scattered areas in the upper sidewall that can be felt when
rubbing the casing. In later stages, the sidewall may appear blistered and
can lead to a sidewall rupture.
APPEARANCE
PROBABLE CAUSE(S)
Deterioration of internal components over time. Fatigue of casing.
Accelerated by overload/underinflation.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove the tire from service. If this condition arises during the warranty period,
consult your tire manufacturer. Otherwise scrap tire.
VEHICLE
None
OPERATIONS
None
29
SIDEWALL
Sidewall Bumps (Blisters)
SIDEWALL
Sidewall Penetration
APPEARANCE
Any damage caused by an object that goes through the sidewall of the tire.
PROBABLE CAUSE(S)
Road debris and, occasionally, vandalism with a sharp
puncturing instrument.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Have the tire inspected by your tire repair supplier to determine repairability.
None
Avoid road hazards.
30
A vertical break through the sidewall occuring between two body ply
cables, that does not break the cables.
APPEARANCE
PROBABLE CAUSE(S) Severe impact. This situation can occur in overinflated and/or
overloaded conditions.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Have the tire inspected by your tire repair supplier to determine repairability.
None
Review inflation maintenance program and review driver training.
31
SIDEWALL
Radial Split
C. Crown Area
33
CASING CONDITIONS -- CROWN AREA
CASING
CONDITIONS
CROWN
Penetrations And Road Hazards
APPEARANCE
Evidence of a puncture or damage by a foreign object through the
crown area; may result in a separation.
PROBABLE CAUSE(S)
Road hazard or foreign object.
EXAMPLE PHOTO & FIGURE
TIRE
ACTION
Determine casing integrity. Consult your repair facility for possibility of repair. If the
damage is excessive and/or a separation is evident, scrap tire.
VEHICLE
None
OPERATIONS
None
34
APPEARANCE
Cut in tread or shoulder area, usually 360˚ around tire.
PROBABLE CAUSE(S)
Contact with vehicle hardware, such as mud flap brackets, trailer
wheel house molding, bumpers, etc.
CROWN
Vehicle Damage
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If cuts are not deeper than the base or the tread groove, return to a dual position. If the
damage is deeper, retread or rebelt if possible. If the condition is more severe, scrap tire.
Analyze the cause of the condition and correct.
Review driving procedures.
35
CROWN
Forklift Damage/Cuts And Snags
APPEARANCE
Individual or multiple cuts, usually in the tread grooves in a localized
area of the crown.
PROBABLE CAUSE(S)
Caused by lift truck forks or similar equipment.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
If the tire is new, determine the responsibility for damage before placing it into service.
If the tire has been in service but no steel is exposed, return to service. If steel is exposed,
retread or rebelt.
None
Inspect new tires upon receipt.
36
APPEARANCE
A bulge or split through the upper sidewall/shoulder area. Probing will
reveal the belts sometimes accompanied by a worn spot in the tread.
PROBABLE CAUSE(S)
Adhesion loss within the tire at the edge of the belt package. May be
associated with a penetration or other damage. Can be aggravated by
spread axle use or dragging tire sideways.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Remove from service and consult your tire manufacturer.
None
Use largest radius turns possible to avoid tire scrubbing.
37
CROWN
Belt Lift/Separation
CROWN
Tread Lift/Separation
APPEARANCE
Bulge on shoulder or tread face area may be accompanied by split
through the bottom of the tread groove. Usually localized wear in the
tread above the separated area will occur. May result in a loss of a
section of tread. Belt package is intact.
PROBABLE CAUSE(S)
Adhesion loss between the tread rubber and the tire casing. Can
be caused by tread penetration.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove tire from service. Consult your tire manufacturer.
VEHICLE
None
OPERATIONS
None
38
Localized spot of excessive wear across the tread face showing
abrasion marks from the tread sliding on the road surface; damage may
extend into the casing.
APPEARANCE
PROBABLE CAUSE(S)
Brake skid usually occurs on trailer and drive tires. Aggravated by new
brakes (high friction, not worn in), unbalanced brake system, aggressive
use of brakes, driver abuse and unloaded vehicles.
CROWN
Brake Skid Damage
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
If condition does not extend below 2/32" of tread, duals can be rematched to position flat
spots 180˚ from each other. If more severe, the tire can be repaired or retreaded if damage
is not into the belts. If skid damage is into the tire belts, it may be possible to remove the
top belt and/or rebelt the tire; consult your retreader. If damage is too excessive, scrap tire.
Check brake materials and brake balance.
Review driving procedures.
39
CROWN
Tread Chunking
APPEARANCE
Sections of tread torn from the tire.
PROBABLE CAUSE(S)
Caused by tire running over curbs or rails or by severe localized
impacts. Aggravated by hot tires, spread axles, sharp turning and off
road utilization.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Remove the tire from service. Repair or retread.
None
Review tire selection. Review driving procedures.
40
APPEARANCE
One or more cracks in the tread rubber located between and at the base of
lugs in the shoulder area.
PROBABLE CAUSE(S)
This condition is caused by a combination of drive axle torque, load and
heat. It also can be due to tire construction or started by stone drilling. It
is aggravated by underinflation.
EXAMPLE PHOTO & FIGURE
TIRE
ACTION
If cracks do not extend into the retread buff line, return to dual wheel service. If
cracks extend deeper, consult your tire manufacturer.
VEHICLE
None
OPERATIONS
None
41
CROWN
Lug Base Cracking
CROWN
Wild Wire
APPEARANCE
Wire protruding through the exterior or interior surface of the tire.
PROBABLE CAUSE(S)
Loose or separated bead or body wires.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your tire manufacturer.
VEHICLE
None
OPERATIONS
None
42
APPEARANCE
Localized break through the tread rubber and the casing.
PROBABLE CAUSE(S)
Severe, concentrated impact with a foreign object or a chuck hole.
Aggravated by overinflation and high speed.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Scrap tire.
VEHICLE
None
OPERATIONS
None
43
CROWN
Impact Breaks
CROWN
Chipping/Flaking/Chunking Tread
APPEARANCE
Rough, abraded tread surface with numerous small flakes or chunks
of tread removed.
PROBABLE CAUSE(S) Operation of tires with over-the-road tread rubber compounds on gravel surfaces and haul roads; misapplication of the tire to service conditions. Aggravated by high torque, over inflation and short turns, especially on drive tires.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
Tires with minor chipping and flaking can be returned to service. If damage extends
below 2/32" retread the tire. If steel is visible, consult your retreader for the possibility
of repair and retread.
None
Review tire selection.
44
APPEARANCE
Damage caused by stones trapped in the tread which penetrate the
tread base and extend into the belts.
PROBABLE CAUSE(S)
Tread design and/or misapplication of the tire to service conditions
(gravel roads/quarry operation).
CROWN
Stone Drilling
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Remove remaining stones and return to service. If penetrations are into the belts, consult the retreader or your tire manufacturer. If unable to retread or rebelt, scrap the tire.
None
Review tire selection.
45
CROWN
Regrooving Damage
APPEARANCE
Exposed belts at the base of the regroove.
PROBABLE CAUSE(S)
Regrooving too deep.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader for the possibility of retreading.
None
Review the cost effectiveness of regrooving.
46
Swollen, spongy area hidden inside the center rib/lug extending up to
360˚ around the tire. Can cause a flat wear spot or may surface as a
localized cavity.
APPEARANCE
PROBABLE CAUSE(S)
Excessive heat buildup on a dynamometer, also on high speed, lightly
loaded overinflated applications using deep lug tires.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader for the possibility of retreading.
None
Review dynamometer procedures. Review load pressure or tire selection.
47
CROWN
Dynamometer Type Damage
CROWN
Chemical Damage
APPEARANCE
Localized spot of blistered, spongy or deteriorated rubber in tread
area.
PROBABLE CAUSE(S)
Exposure to chemicals, usually solvent in nature, which attack tread
rubber.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Depending upon extent of chemical damage, return to trailer service or retread tire.
VEHICLE
None
OPERATIONS
None
48
APPEARANCE
Tire worn to point of exposing casing reinforcement material.
PROBABLE CAUSE(S)
Run too long in service or brake skid.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Retread and rebelt if possible; otherwise scrap tire.
VEHICLE
None
OPERATIONS
None
49
CROWN
Excessive Wear
CROWN
Rib Tearing
APPEARANCE
Tear at the base of the main tread grooves, generally at the shoulder;
no tread missing.
PROBABLE CAUSE(S) Caused by running over curbs and rails, or by severe localized impacts,
aggravated by spread axles, hot tires and sharp turning.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If steel is showing, consult your tire manufacturer. If steel is not evident, retread or
return to service on a dual position.
None
Review driving procedures.
50
APPEARANCE
Tear at the base of the defense groove (decoupling groove, stress
relief groove, shoulder groove).
PROBABLE CAUSE(S)
Caused by running over curbs or rails, or by severe localized impacts,
aggravated by sharp turning.
CROWN
Defense Groove Tearing
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If steel is visible, contact your tire manufacturer. If the tear extends near the buff radius,
consult your retreader for possible retread. Otherwise return to service.
None
Review driving procedures.
51
CROWN
Groove Cracking
APPEARANCE
Areas at the base of the grooves with cracks.
PROBABLE CAUSE(S)
This condition is caused by high side forces applied to a rib type tire.
It can also be caused by petroleum damage, weathering, or exhaust on
drive tires.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If cracking is superficial, continue tire in service. If cracks are greater than 2/32" or more
past the bottom of the groove, contact your tire manufacturer.
Review exhaust routing.
Review driving procedures in tight turns.
52
APPEARANCE
Circumferential cuts or lines around tire.
PROBABLE CAUSE(S)
Spinning drive tires on ice, sand, gravel, etc.
CROWN
Spin Damage
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
Place the tire back into service if the damage does not extend beyond the base of the
tread groove. If damage is deeper, retread or rebelt if possible. If the condition is more
severe, scrap tire.
None
Review driving procedures and/or drive tire selection.
53
D. Tire Interior
55
CASING CONDITIONS -- TIRE INTERIOR
CASING
CONDITIONS
INTERIOR
Penetrating Objects
APPEARANCE
Foreign object protruding through the interior surface of the tire.
PROBABLE CAUSE(S)
Impact with road hazard.
EXAMPLE PHOTO & FIGURE
TIRE
ACTION
Remove foreign object. Inspect degree of damage. Repair if permissible according to
repair limit standards, and restore moisture seal and air retention integrity. If damage is
excessive, scrap tire.
VEHICLE
None
OPERATIONS
None
56
APPEARANCE
Split in the rubber of the tire inner liner at the juncture of the inner
liner material.
PROBABLE CAUSE(S)
Loss of adhesion at the splice due to excessive flexing from
underinflation; may also be manufacturing related.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Repair inner liner with rubber gum to ensure air retention integrity if ply cords
are not exposed. If ply cords are visible, contact your tire manufacturer.
VEHICLE
None
OPERATIONS
None
57
INTERIOR
Open Inner Liner Splice
INTERIOR
Inner Liner Bubbles, Blisters And Separations
APPEARANCE
Bubble or blister in the tire interior.
PROBABLE CAUSE(S)
Adhesion loss of inner liner material to the casing.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove from service and contact your tire manufacturer. If blisters are small and few,
the inner liner can be repaired and the tire can be placed back into service.
VEHICLE
None
OPERATIONS
None
58
APPEARANCE
One or more cracks in the inner liner at locations other than the inner
liner splice.
PROBABLE CAUSE(S)
Under inflation, excessive heat buildup in the tire interior. May also
be manufacturing related.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Remove the tire from service and contact your tire manufacturer.
VEHICLE
None
OPERATIONS
None
59
INTERIOR
Inner Liner Cracking
INTERIOR
Pulled/Loose Cords
APPEARANCE
Depression or elevation in the surface of the tire interior along the
radial cord path.
PROBABLE CAUSE(S)
Impacts, penetrations, poor repairs and under inflation which damage
ply material.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Scrap tire.
VEHICLE
None
OPERATIONS
None
60
APPEARANCE
Tearing or loss of adhesion of the inner liner material inside the bead
toe area.
PROBABLE CAUSE(S)
Poor mounting/demounting techniques or lack of lubricant.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Repair the inner liner or scrap the tire if damage is too excessive.
None
Review tire mounting/dismounting procedures and the use of tire tools.
61
INTERIOR
Tearing, Mount/Dismount Damage
INTERIOR
Foreign Object Inner Liner Damage In Tubeless Tire
APPEARANCE
A series of random cuts or abrasion marks around the circumference
of the tire interior, not otherwise explained.
PROBABLE CAUSE(S)
Foreign object in tire.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Inspect for degree of damage, repair if possible; otherwise scrap the tire.
VEHICLE
None
OPERATIONS
None
62
APPEARANCE
Discoloration, blistering and/or separations of the inner liner.
PROBABLE CAUSE(S)
Continued operation after loss of inflation pressure.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Scrap the tire.
VEHICLE
None
OPERATIONS
None
63
INTERIOR
Run Flat
INTERIOR
Pinch Shock
APPEARANCE
A horizontal, crescent shaped crease or break in the inner liner in the
sidewall area. A small bulge may also appear in the damaged area.
PROBABLE CAUSE(S)
Severe impact.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Have the tire inspected by your tire repair supplier to determine repairability.
Severe impacts can cause bent rim flanges. Inspect wheels and recheck alignment.
Review driving procedures and driver education.
64
APPEARANCE
Crack or break in tire interior surface. May be accompanied by
pulled or loose cords.
PROBABLE CAUSE(S)
Sudden and excessive force applied to the tire exterior which exceeds
reinforcing material limits. May be caused by road hazard or driver
abuse.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Scrap tire.
None
Review driving procedures.
65
INTERIOR
Impact Break
E. Any Area
67
CASING CONDITIONS -- ANY AREA
CASING
CONDITIONS
ANY AREA
Run Flat
APPEARANCE
Advanced deterioration of radial tire affecting 360° of tire sidewall.
PROBABLE CAUSE(S) Loss of inflation pressure. Diagnosis of cause of inflation loss becomes
difficult or impossible as this condition progresses.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Scrap the tire.
VEHICLE
None
OPERATIONS
None
68
Random oriented cracking on tire, sometimes associated with holes or
punctures not otherwise explained.
APPEARANCE
PROBABLE CAUSE(S) Vehicle contact with electrical cables or lightning.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Scrap the tire.
VEHICLE
None
OPERATIONS
None
69
ANY AREA
Electrical Discharge
Section II:
Retread and
Repair Conditions
71
Introduction to Retread Conditions
The area involved in retread conditions is located in the crown area of the tire, and the tire conditions
covered in this section are divided into categories that describe their appearance. These categories
are: Holes and Injuries, Missing Tread, Cracks, Bulges, and Miscellaneous.
Holes and Injuries are normally caused by in-service impacts and/or penetrations. Many are repairable. Others, due to the severity of the injury, render the casing unfit for further use.
Many casings which are scrapped could be repaired and returned to service—providing proper repair
and/or sectioning procedures are followed. Other casings may be repaired and returned to restrictive
service.
Irregular wear can be caused by many factors usually related to vehicular irregularities rather than tire
or retread anomalies. The conditions cited in this guide will deal with retread problems rather than
misalignment, mismatching, etc.
Separation of the tread from the casing can be caused by any number of factors and each of these must
be diagnosed separately. Some cracks require immediate attention while others can run out the life of
the tread. There are three major causes of cracks: (1) operational abuse, (2) retreading conditions, and
(3) new tire manufacturing conditions.
Bulges can be cause by trapped air between the internal components of the tire or between the tire and
the retread. In addition, breaks in the body cords can permit a deformation of the casing. Bulges, in
general, are an indication of a weakness in the tire which may lead to a tire failure. Upon discovery of
a bulge in a tire, the bulge should be outlined with a tire crayon, removed from service and inspected
for disposition.
The Miscellaneous category consists of other retread conditions which look severe yet may not affect
the tread life. They are cosmetic in nature and usually are the result of poor retread workmanship.
These discrepancies should have been caught during the retreader's final inspection. The retreader
should be made aware of your concern and then take corrective action.
72
A. Holes and Injuries
73
RETREAD CONDITIONS -- HOLES AND INJURIES
RETREAD
CONDITIONS
HOLES
Bad Spot Repair
APPEARANCE
The repair fill-rubber is missing or loose in the sidewall or tread area
and sometimes exhibits cracks.
PROBABLE CAUSE(S)
Poor workmanship. Contaminated buffed area, improper cementing,
contaminated fill material, improper cure time or pressure, improper
injury removal, etc.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair
if possible or scrap the tire if it is unrepairable.
None
None
74
The repair fill-rubber is missing or loose from a sidewall spot repair.
Ply cords may be exposed. A distortion or separation is evident
inside the tire.
APPEARANCE
PROBABLE CAUSE(S)
Poor workmanship. Not all the injury was removed. A full reinforced section repair should have been made.
EXAMPLE PHOTO & FIGURE
TIRE
ACTION
Consult your retreader/repair person for possible warranty adjustment. Re-repair
if possible or scrap the tire if it is unrepairable.
VEHICLE
None
OPERATIONS
None
75
HOLES
Spot Repair Should Be A Section Repair
HOLES
Improper Nail Hole Repair
APPEARANCE
PROBABLE CAUSE(S)
Interior: A crack or split extends from the repair unit. The repair unit
may be dimpled, cracked or loose. Some signs of heat build up may be
evident such as powdery or sticky rubber. Exterior: Separation of tire
components may be evident in advanced stages.
Nail hole repair procedures were used instead of section repair
procedures resulting in inadequate injury removal. An improper size
and type of repair unit was used.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair if
possible, otherwise scrap the tire.
None
Review repair techniques with your repair person.
76
APPEARANCE
Interior: The repair unit may be dimpled, lifted or cracked. The repair
unit alignment arrows do not point in the proper direction.
Exterior: Tire components may be separated.
PROBABLE CAUSE(S)
Improperly installed repair unit. (In this case, the bead arrows do not
point to the beads.) Improperly trained repair personnel.
HOLES
Improperly Aligned Repair
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair if
possible, otherwise scrap the tire.
None
Review repair techniques with your repair person.
77
HOLES
Unfilled Nail Hole Repair
APPEARANCE
Interior: The repair unit is dimpled or cracked. Exterior: Rust is
evident in the unfilled hole.
PROBABLE CAUSE(S) The injury was not filled with a plug or rubber fill material.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair
if possible, otherwise scrap the tire.
None
Review repair requirements with road service vendors and monitor on the road
tire service.
78
Interior: The repair unit is loose, split or torn in the tire's shoulder area.
A bulge, polished or gooey area caused by excessive heat may be evident
under the repair unit. The fill material may also be cracked. Exterior: A
sidewall bulge may be evident and the fill material may be cracked. Tire
components may be separated.
APPEARANCE
PROBABLE CAUSE(S) Improper placement of the repair unit during installation which resulted
in trapped air under the repair unit. The tire beads were probably spread
during installation of the repair unit.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair if
possible, otherwise scrap the tire.
None
Review repair techniques with your repair person.
79
HOLES
Bridged Repair
HOLES
On the Wheel Repair
Interior: A rubber-coated cord or a cured rubber plug is used to fill the
hole with no repair unit covering the injury. Cracks or separation around
the hole may be evident. Further damage from penetrating objects may
also be evident. Exterior: The tread or tire components may be
separated.
The tire was not demounted and properly inspected and repaired. This
PROBABLE CAUSE(S) type of repair is not recommended.
APPEARANCE
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair
if possible, otherwise scrap the tire.
None
Review repair requirements with road service vendors and monitor on the road
tire service.
80
Interior: The inner liner may be separated and the bead area may exhibit
exposed fabric or steel, cracking, loose rubber and/or improper bead
contour. Exterior: Separation of the tire components may be evident.
APPEARANCE
PROBABLE CAUSE(S) The injury exceeds repair limitation, poor workmanship, improper cure,
incorrect fill material, or poor mounting/demounting techniques.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair
if possible, otherwise scrap the tire.
None
Review mounting/demounting procedures to eliminate bead damage.
81
HOLES
Bad Bead Repair
HOLES
Failed Repair - Injury Not Removed
APPEARANCE
PROBABLE CAUSE(S)
Interior: A split/crack extends from under the repair unit. The repair
unit may also be torn loose or be missing. Exterior: Tire components
may be separated leaving rusty, loose cords.
All injury or separation was not detected and removed during the
repair process, poor workmanship.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment.
Scrap the tire.
None
Review repair techniques with your repair person.
82
PROBABLE CAUSE(S)
Interior: The repair unit is cracked or distorted. Bias repair units
may be round or "X" shaped and are not labeled "Radial" (All radial,
reinforced tire repair units are marked "Radial.") Exterior: Tire
components may be separated.
PROBABLE CAUSE(S)
An incorrect repair unit was installed, improperly trained personnel.
APPEARANCE
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader/repair person for possible warranty adjustment. Re-repair if
possible, otherwise scrap the tire.
None
Review repair techniques with your repair person.
83
HOLES
Bias Repair in Radial Tire
B. Missing/Loose Tread
85
RETREAD CONDITIONS -- MISSING TREAD
RETREAD
CONDITIONS
TREAD
Bond Line Porosity
APPEARANCE
PROBABLE CAUSE(S)
Large sections, if not all, of tread has separated from the casing;
porosity is evident. This appears as a sponge-like surface that is
frequently tacky.
Lack of proper cure conditions, i.e., time, temperature and pressure.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader for possible warranty adjustment. Retread and rerun.
VEHICLE
None
OPERATIONS
None
86
APPEARANCE
A portion of tread rubber only, located in any area of the tire, lifts
and separates from the buffed surface of the tire body.
PROBABLE CAUSE(S)
Faulty retread workmanship and/or material such as a scorched or
contaminated buffed surface, old cushion gum or tread rubber, improper cure conditions, missed nail hole, or a faulty repair.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader for possible warranty adjustment. Retread the tire again.
VEHICLE
None
OPERATIONS
None
87
TREAD
Tread Separation
TREAD
Tread Chunking At Splice
APPEARANCE
Portion(s) of tread are missing in the area of the tread splice in a precured retread.
PROBABLE CAUSE(S)
Improper workmanship or contamination at the splice.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Run out the tread in the desired position or consult your retreader for a tread spot
repair. Retread again if possible.
VEHICLE
None
OPERATIONS
None
88
APPEARANCE
A portion of the tread is separated from the buffed surface. A repair
is evident in the area of the separated tread.
PROBABLE CAUSE(S)
Faulty repair. Air seeped through or was trapped in the injury and
under the tread which eventually reduced adhesion between the tread
and the tire and resulted in a separation.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader and/or repairman for possible warranty adjustment or repair
and retread the tire again.
None
Consult your repairman to correct repair problem.
89
TREAD
Tread Separation - Repair Related
TREAD
Belt Separation - Repair Related
APPEARANCE
Exterior: The tread and one or more belts is loose or missing from a
portion or from the whole tire. A repair or skive is evident in the area of the
separation. Interior: The repair unit may be sunk, dimpled, or cracked.
PROBABLE CAUSE(S) A faulty repair or skive. Air migrated through the injury causing separation between the belts.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your repairman and/or retreader for possible warranty adjustment. Scrap
the tire.
VEHICLE
None
OPERATIONS
None
90
A portion of the tread is separated from the casing at the buff line in
the area of the unrepaired puncture. This usually occurs soon after
retreading.
APPEARANCE
PROBABLE CAUSE(S)
An undetected and unrepaired penetration.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader for possible warranty adjustment. Retread again if possible.
VEHICLE
None
OPERATIONS
None
91
TREAD
Missed Puncture
TREAD
Tread Edge Lifting
APPEARANCE
The tread is worn to excess on one shoulder of the tire; the edge of the
tread is loose and exhibits more wear in the area of separation.
PROBABLE CAUSE(S)
Caused by cure related problems, retread processing problems, the
shoulder buffed lower on one side or possible belt edge separation.
EXAMPLE PHOTO & FIGURE
TIRE
ACTION
Consult your retreader for possible warranty adjustment. If the tire casing is sound,
retread the tire. If the belt is separating from the casing, consult the original tire
manufacturer.
VEHICLE
None
OPERATIONS
None
92
C. Cracks
93
RETREAD CONDITIONS -- CRACKS
RETREAD
CONDITIONS
CRACKS
Failed Inner Liner Repair
APPEARANCE
Interior: A crack extends from the repair rubber. Buff marks may be
visible around the repair rubber. The repaired area may be coated
with liner sealer. Exterior: Tire components may be separated.
PROBABLE CAUSE(S) An attempt to repair liner blisters or an open liner splice failed to seal
the air cavity of the tire and air migrated into the tire body causing
separation.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader for possible warranty adjustment. Scrap the tire.
VEHICLE
None
OPERATIONS
None
94
Cracking is evident at the base of the tread lugs. Some lugs may be torn
from the tread in severe cases.
APPEARANCE
PROBABLE CAUSE(S) The wrong tread design was used for the operation (single axle, high torque
drive application with deep traction tread design may contribute to this
condition), rubber compound, excessive or lack of undertread, over curing.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader for possible warranty adjustment. Retread if possible.
None
Review tread design selection for application.
95
CRACKS
Lug Base Cracking
CRACKS
Improper Tread Width
APPEARANCE
A crack appears at the tread edge which can extend into the belt. The
tread edge may lift off the casing.
PROBABLE CAUSE(S)
Inadequate support of the belt package during operation which creates
a new flex point in the tire. The result is a breakdown of the belts or
rubber at the bondline of the retread and the casing.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consult your retreader for possible warranty adjustment.
None
None
96
APPEARANCE
A space is evident between the tread ends.
PROBABLE CAUSE(S)
Poor workmanship, poor tread end adhesion or the tread was cut too
short.
CRACKS
Open Tread Splice
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
The tire may run out its tread life and be returned to service; or consult your retreader for
possible warranty adjustment and retread again.
VEHICLE
None
OPERATIONS
None
97
D. Bulges / Depressions
99
RETREAD CONDITIONS -- BULGES / DEPRESSIONS
RETREAD
CONDITIONS
BULGES
Skive Failure
APPEARANCE
A bulge or excessive wear in the tread area, or area where the tread is
missing at a skive.
PROBABLE CAUSE(S)
Improper skive or skive fill which traps air or allows air to seep under
the tread and results in a localized loss of tread adhesion. Tread or
casing separation may occur if not caught early in treadlife.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader for possible warranty adjustment. If within limits of repair, repair
the tire again and retread.
VEHICLE
None
OPERATIONS
None
100
APPEARANCE
An excessive bulge in the mid/upper sidewall which may progress to a
complete separation of the sidewall rubber from the casing. A slight
bulge associated with a repair which can be identified with a blue
triangular label is normal as the cables reposition themselves after repair.
The bulge must not exceed 3/8".
PROBABLE CAUSE(S)
The repair unit is too small or improperly installed.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If the bulge exceeds 3/8", scrap the tire.
None
Consult your tire repairman to correct the repair problems.
101
BULGES
Repair Related Bulge
BULGES
Buckled Tread
APPEARANCE
Undulations are evident in the tread surface and interior of a mold
cured retread.
PROBABLE CAUSE(S)
The retread tire was too large for the mold in which it was cured, thus
causing distortion in the tire during the curing process.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader/repair person for possible warranty adjustment.
VEHICLE
None
OPERATIONS
None
102
E. Miscellaneous
103
RETREAD CONDITIONS -- MISCELLANEOUS
RETREAD
CONDITIONS
MISC.
Delamination
APPEARANCE
Evidence of layers of rubber in the tread.
PROBABLE CAUSE(S)
Excessive mold lube or a rubber compounding problem, surface cure of
the tread rubber or poor mold fitment.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
The tread can be run out if the condition is not severe, otherwise consult your retreader
for possible warranty adjustment and retread the tire again.
VEHICLE
None
OPERATIONS
None
104
APPEARANCE
A spongy appearance in the surface of the tread. Portions of the tread
may be missing.
PROBABLE CAUSE(S)
Insufficient tread rubber, improper cure, or poor mold fitment.
MISC.
Tread Surface Porosity
EXAMPLE PHOTO & FIGURE
TIRE
ACTION
The tread can be run out if the tread adhesion to the casing is adequate, however, tread
wear may be poor. If the adhesion is poor, consult your retreader for possible warranty
adjustment, and retread the tire again.
VEHICLE
None
OPERATIONS
None
105
MISC.
Wing Lift
APPEARANCE
PROBABLE CAUSE(S)
The sidewall shoulder rubber of the retread is loose.
Lack of shoulder buff or poor mold fitment (mold cure), poor tread
building, scorched or contaminated buffed surface and/or improper
crown radius.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Consult your retreader for possible warranty adjustment. Retread again.
VEHICLE
None
OPERATIONS
None
106
APPEARANCE
Cracks in the repair unit, cracks emanating from the repair unit, loose
edges under the repair unit, tacky surface around the repaired area or
under the repair unit.
PROBABLE CAUSE(S)
Running the tire underinflated due to a puncture, cut, bad valve stem,
lack of proper air pressure, etc.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Repair again if permissible according to repair limit standards. If the failure
cannot be re-repaired, scrap tire.
None
Review tire inflation maintenance procedures and load conditions.
107
MISC.
Failed Repair From Underinflation
Section III:
Radial Tire Wear
Conditions and Causes
109
Introduction to Radial Tire Wear
Conditions and Causes
To get maximum tread life from radial tires and reduce tire costs/mile, it is essential to minimize uneven tread
wear and possible casing damage. Section III of this manual provides a reference source and training aid which
will assist the user in identifying radial tire wear patterns and determining causes which can then be corrected
to minimize irregular wear.
The advantages of radial tires are that they are slow wearing which prolongs tread life, and they provide a long
footprint which reduces scrubbing and results in improved fuel economy. Another advantage is improved
casing durability which provides a potential cost-savings through additional retreads. However, these attributes
of the radial design can also result in the tire exhibiting more irregular wear patterns when vehicle and tire
maintenance or tire construction is inadequate. These wear patterns are not as evident in short haul, high torque
operations since the tread wears away much faster and unusual wear patterns are often literally scrubbed off.
Some common causes of the various tire wear patterns which have been identified are as follows:
Maintenance and Operations
• Misalignment on steer, drive, trailer and dolly axles
• Improper inflation maintenance
• Mismatching of tires, especially in dual applications
• Incorrect mounting of the tire on the rim and resulting improper bead seating
• Non-uniformity of the rotating assembly - tire, wheel/rim, brake drum, hub
• Excessive imbalance and/or run-out
• Improper loads for the service application
• Tire misapplication - Use of an improper tire for the axle position or service condition
• Poorly maintained suspensions with looseness in components, or incorrect replacement parts
• Improper use of chains or other traction assists
• Poor driver practices
Tires
• Non-uniformity in balance and/or runout
• Inadequate tire design or construction
Wheels/Rims/Brake Drums/Hubs
• Non-uniformity in balance and/or runout, stud circle concentricity
Inflation maintenance and misalignment on steer, drive, trailer and dolly axles are highlighted under
maintenance-related causes of irregular wear patterns. These represent the most common causes for irregular
wear patterns and generally have the most severe impact on tire wear when compared with other causes.
Inadequate inflation maintenance is a continuous cause that is often overlooked, while misalignment is
probably the least understood and often the last to be corrected.
110
A. Steer Axle Tires
111
RADIAL TIRE WEAR —STEER AXLE TIRES
RADIAL TIRE
WEAR CONDITIONS
AND CAUSES
Shoulder Step/Chamfer Wear
APPEARANCE
STEER AXLE TIRES
PROBABLE CAUSE(S)
Even tread wear in center with steps worn in shoulders. This is confined
to the outer portion of the shoulder rib. Can be wider on one shoulder
than the other.
Typical of radial tires in slow wearing operations. May vary with tread
design and service application.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Little or no loss in overall mileage will result provided tread depth differential is not
excessive. Tires can remain on the steer axle.
VEHICLE
None
OPERATIONS
None
112
Full Shoulder Wear
APPEARANCE
Excessive wear extending across entire shoulder rib to a major tread
groove, usually on one side of tire only.
PROBABLE CAUSE(S)
Result of side scrubbing and generally is caused by either improper toe
condition or drive axle misalignment.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If wear is severe, tires can be rotated to another position or reversed on the wheel.
Diagnose misalignment, check suspension components, and correct as required.
None
113
STEER AXLE TIRES
In case of toe in, the outside shoulders of both steer tires will be worn,
while in the case of toe out, the inside shoulders of both steers will be
worn. Drive axle misalignment wears the inside shoulder of one tire and
the outside shoulder of the other steer tire. Poorly maintained suspension components (e.g. torque rods, springs, and spring bushings) can
produce the same results.
STEER AXLE TIRES
Feather Wear
APPEARANCE
Tread ribs worn so that one side of rib is higher than the other resulting
in step-offs across the tread face. Generally, all ribs exhibit this wear.
PROBABLE CAUSE(S)
Excessive side force scrubbing, resulting from severe conditions of
misalignment such as excessive toe, severe drive axle misalignment,
worn, missing or damaged suspension components, bent tie rod or other
chassis misalignment.
EXAMPLE PHOTO & FIGURE
TIRE
VEHICLE
OPERATIONS
ACTION
If feather wear is severe, tires can be rotated to another axle for maximum utilization of
remaining tread.
Diagnose and correct misalignment condition as required. If feather wear on both steer
tires is in the same direction, drive axle or other chassis misalignment is indicated. If
steer tire feathers are in opposite directions, a toe condition is indicated.
None
114
Erosion/River/Channel Wear
APPEARANCE
Circumferential wear along rib edges next to major tread grooves may
be wavy in appearance and vary in width around tire.
PROBABLE CAUSE(S)
Characteristic of slow wear rate of radial tires on free rolling axles. May
vary with individual tire tread design and construction. Common in line
haul operations in which loads are light and turning is frequent.
EXAMPLE PHOTO & FIGURE
STEER AXLE TIRES
ACTION
TIRE
Erosion wear should not be of concern.
VEHICLE
None
OPERATIONS
None
115
STEER AXLE TIRES
Cupping/Scallop Wear
APPEARANCE
Localized dished out areas of fast wear creating a scalloped appearance
around tire. Appears around the tire on the shoulder ribs. May progress
to adjoining ribs.
PROBABLE CAUSE(S)
Usually a result of moderate to severe assembly out of balance condition,
improper rim/wheel mounting or other assembly non-uniformity. Can
also be due to lack of shock absorber control on some suspension types.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If ride complaints arise, tires may be rotated to drive axle.
Diagnose imbalance condition, i.e., wheel, rim, hub, brake drum. Correct as necessary.
None
116
One-Sided Wear
APPEARANCE
Excessive wear on one side of tire extending from the shoulder towards
the center of the tread.
PROBABLE CAUSE(S)
Improper alignment, worn king pins, loose front wheel bearings, excessive axle loads.
EXAMPLE PHOTO & FIGURE
STEER AXLE TIRES
ACTION
TIRE
VEHICLE
OPERATIONS
Depending on severity of wear, tires may be rotated to drive axle or, if worn to minimum
tread depths on shoulder, submit for possible retreading.
Diagnose mechanical problem and correct.
None
117
STEER AXLE TIRES
Diagonal Wear
APPEARANCE
Localized flat spots worn diagonally across the tread, often repeating
around tread circumference.
PROBABLE CAUSE(S)
Runout and/or out of balance in conjunction with a slow rate of wear.
Can develop from a brake skid, spot wear, shoulder wear, or other
advanced wear conditions. Can also be caused by loose wheel bearings
and is aggravated by misalignment.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
The tire may be rotated to the outside drive dual position with change in rotation of the
tire. If wear is excessive, submit to retreader for further options.
Diagnose cause and correct.
None
118
Eccentric/Out-Of-Round Wear
APPEARANCE
Considerable difference in tread depth between 90˚ and 180˚ apart.
PROBABLE CAUSE(S)
Usually a result of excessive radial runout or other non-uniformity in the
rotating assembly, e.g. hub, stud circle, wheel/rim, tire and/or improper
bead seating of tire on rim. May also be caused by dragging or distorted
brake drums and drums with excessive wall thickness variation. May be
accompanied by, or develop into, a vibration complaint.
STEER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Tire may be rotated to the trailer dual. If wear is excessive on worn side, submit to
retreader for further options.
Diagnose problem components/parts. Replace or correct as necessary.
None
119
STEER AXLE TIRES
Overall Fast Wear
APPEARANCE
Good wear pattern but fast rate of wear.
PROBABLE CAUSE(S)
Can be caused by service conditions such as mountainous terrain,
frequency and severity of turning, abrasive road surfaces in combination with vehicle configurations and their attributes such as power
steering, heavy axle loads, high wheel cuts, setback axles, short wheel
base tractors, long wheel base straight trucks.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
None
Consult vehicle and tire manufacturers when specing equipment or replacing tires.
None
120
Rib Depression/Punch Wear
APPEARANCE
One or more inner ribs worn below the level of the adjacent ribs
circumferentally around the tire.
PROBABLE CAUSE(S)
Lack of shock absorber control in some suspension types, improper
inflation pressures, loose or worn wheel bearings, assembly non-uniformity such as improper bead seating and out-of-balance condition, aggravated by high speed empty hauls.
STEER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If not worn excessively, continue to run. If wear is excessive, retread.
Diagnose mechanical problem and correct.
None
STEER AXLE TIRES
Erratic Depression Wear
APPEARANCE
Random, erratic wear around tire circumference.
PROBABLE CAUSE(S)
Lack of shock absorber control in some suspension types. Loose or
worn wheel bearings, assembly non-uniformity such as improper bead
seating and out-of-balance condition, aggravated by high speed empty
hauls.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If not worn excessively, continue to run. If wear is excessive, retread.
Diagnose mechanical problem and correct.
None
122
B. Drive Axle Tires
121
RADIAL TIRE WEAR —DRIVE AXLE TIRES
RADIAL TIRE
WEAR CONDITIONS
AND CAUSES
DRIVE AXLE TIRES
Shoulder Step/Chamfer Wear
APPEARANCE
Tire worn on edge of shoulder. This is confined to the outer portion of
the shoulder. Can be wider on one shoulder than the other. This condition usually appears first on the inside shoulder of the inside dual of the
front drive axle.
PROBABLE CAUSE(S)
Typical of radial tire construction and slow rates of tread wear. May
vary with tread design and service application. Can be aggravated by
axle deflection, road conditions, and worn or damaged suspension parts.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Consider rotating tire among drive axles. Does not adversely affect overall tread life.
Inspect for worn or damage suspension parts.
None
124
Heel/Toe Wear
APPEARANCE
Each lug around tire worn high to low from front to back edge.
PROBABLE CAUSE(S)
Most often caused by mismatched inflation pressures or tire diameter
in a dual assembly and certain conditions such as P&D operations,
mountainous terrains, etc.
DRIVE AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Run out on drive axle. If severe, change direction of rotation until tread is worn
to point of retread.
Review tire maintenance practices and tread design selection.
None
125
DRIVE AXLE TIRES
Alternate Lug Wear
APPEARANCE
Alternate lugs worn to different tread depths around tire circumference.
May be every second lug, every third, etc... or a combination thereof.
PROBABLE CAUSE(S)
Mismatched inflation pressures or tire diameters in a dual assembly and
certain conditions such as pick up and delivery operations and variations
in loads. Is accentuated by slow rate of tire wear and by worn or poorly
maintained suspension components or axle misalignment.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Continue to run out unless tread depth variations become severe. Rotate to faster wearing
position, i.e., single screw tractor or rear drive axle.
Check for worn or damaged components and axle misalignment.
Review tire maintenance practices and tread design selection.
126
Brake Skid/Flat Spot Wear
Flat spot on tread surface. Surface texture may show abrasion marks
from tread sliding on road surface, but surface may have since worn
smooth. Often exhibited on more than one tire position on an axle.
APPEARANCE
PROBABLE CAUSE(S)
Aggravated by new brakes (high friction, not worn in), unbalanced brake
system, aggressive use of brakes and driver abuse. Sometimes seen on
new vehicle drive-aways.
EXAMPLE PHOTO & FIGURE
DRIVE AXLE TIRES
ACTION
TIRE
VEHICLE
OPERATIONS
If condition is not excessive, duals can be rematched to position flat spots 180° from each
other. If more severe, the tire can be repaired or retreaded if damage is not into the belts.
If skid damage is into the tire belts, it may be possible to remove the top belt and/or rebelt
and then retread the tire. Consult your retreader. If damage is excessive, scrap tire.
Check brake material and brake balance.
Review driver training program.
127
DRIVE AXLE TIRES
Overall Fast Wear
APPEARANCE
Uniform wear pattern, but fast rate of wear.
PROBABLE CAUSE(S)
Can be caused by service conditions such as mountainous terrain,
frequency and severity of turning, abrasive road surfaces and equipment
such as single axle drive, long wheel base straight trucks, heavy axle
loads, high horsepower engines, or mismatched drive train components.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Continue to run and retread. If condition continues, consult tire manufacturer
Review tire design selection. Carefully match equipment with service requirements.
Consult vehicle and tire manufacturer when specing equipment or replacing tires.
None
128
C. Trailer Axle Tires
129
RADIAL TIRE WEAR —TRAILER AXLE TIRES
RADIAL TIRE
WEAR CONDITIONS
AND CAUSES
Brake Skid/Flat Spot Wear
APPEARANCE
TRAILER AXLE TIRES
PROBABLE CAUSE(S)
Localized spot of excessive wear across the tread face. Surface texture
may show circumferential abrasion marks from tread sliding on road
surface, but surface may have since worn smooth. Usually exhibited on
both tires in a dual assembly.
Brake skid occurs most often on dolly, trailer and drive tires. Aggravated by new brakes (high friction, not worn in), unbalanced brake
system, aggressive use of brakes, frozen brakes and driver abuse such as
the use of only trailer brakes to stop a vehicle. Sometimes seen on new
vehicle drive-aways.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If condition is not excessive, duals can be rematched to position flat spots 180˚ from each
other. If more severe, the tire can be repaired or retreaded if damage is not into the belts.
If skid damage is into the tire belts, it may be possible to remove the top belt and/or rebelt
the tire. Consult your retreader. If damage is excessive, scrap tire.
Check brake material and brake balance.
Review driver training program.
130
Diagonal Wear
APPEARANCE
Localized flat spots worn diagonally across the tread at approximately
25˚-35˚ angles often repeating around tread circumference.
PROBABLE CAUSE(S)
Bad wheel bearings, toe out, mismounting of tire and wheel assembly to
trailer, mismatched duals for size and/or inflation pressures; may start as
brake skid. Aggravated by high speed empty or light load hauls.
TRAILER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Reverse direction of rotation of the tire. If wear is excessive, true or retread
Diagnose cause and correct.
None
131
TRAILER AXLE TIRES
Multiple Flat Spotting Wear
APPEARANCE
Numerous areas worn flat around circumference or tread.
PROBABLE CAUSE(S)
Uneven dual loading due to mismatched inflation pressures or tire sizes,
worn wheel bearings, imbalance, air suspensions with bad shocks, driver
abuse of trailer brakes; aggravated by high speed empty hauls.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If not worn excessively, run tires out. If remaining tread at worn spots is 2/32" or less,
retread tire.
Diagnose cause and correct.
Consult driver and review maintenance practices.
132
Rapid Shoulder Wear - One Shoulder
Tire worn on edge of one shoulder sometimes extending to inner ribs.
Can progress to diagonal wipeout.
APPEARANCE
PROBABLE CAUSE(S) Excessive toe, excessive camber. These conditions can be created by a
misaligned or bent axle and can also be caused by loose or worn wheel
bearings.
TRAILER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Change direction of rotation of tire. If shoulder wear is severe, remove and retread.
Diagnose misalignment and/or mechanical condition and correct.
None
133
TRAILER AXLE TIRES
Shoulder Scrubbing/Scuffing
APPEARANCE
Abrasion on upper tire sidewall near tread edge. Can be accompanied
by cracks in tread shoulder area.
PROBABLE CAUSE(S)
Excessive lateral scuffing of tread, especially in tight turns when tire is
hot. Most common on heavily loaded, spread axle trailers.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Move affected shoulders to low scrub positions. If severe, tire removal may be required.
Inspect for serviceability on another axle or retread if possible.
VEHICLE
None
OPERATIONS
None
134
Rapid Shoulder Wear - Both Shoulders
APPEARANCE
Full rib wear on both shoulders.
PROBABLE CAUSE(S) Frequently found on spread axles as a result of normal service conditions. Also found on dolly axles as a result of the push/pull action of
that operation.
TRAILER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If shoulder wear is severe, remove and retread.
None
Review tire application with tire manufacturer.
135
TRAILER AXLE TIRES
Erratic Depression Wear
APPEARANCE
Random, erratic wear around tire circumference.
PROBABLE CAUSE(S)
Lack of shock absorber control in some suspension types, mismatched
tire sizes and/or inflation pressures between duals, loose or worn wheel
bearings, assembly non-uniformity such as improper bead seating and
out-of-balance condition, aggravated by high speed empty hauls.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If not worn excessively, continue to run. If wear is excessive, retread.
Diagnose mechanical problem and correct.
None
136
One Sided Wear
APPEARANCE
Excessive wear on one side of tire.
PROBABLE CAUSE(S)
Excessive toe, excessive axle camber, non-parallel axles, non-uniform
tire and wheel assembly caused by improper bead seating or a bent
wheel.
TRAILER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
Change tire position on trailer. If excessive, retread.
Isolate and correct cause.
None
137
TRAILER AXLE TIRES
Erosion/River/Channel Wear
APPEARANCE
Localized wear along inside edges of tread ribs which may be wavy in
appearance and vary in width around the tire.
PROBABLE CAUSE(S)
Characteristic of slow wear rate of radial tires on free rolling axles. May
vary with individual tire tread design and construction.
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
Erosion wear should not be of concern.
VEHICLE
None
OPERATIONS
None
138
Rib Depression/PunchWear
APPEARANCE
One or more inner ribs worn below the level of the adjacent rib around
the tire's circumference.
PROBABLE CAUSE(S)
Lack of shock absorber control in some suspension types, mismatched
tire sizes and/or inflation pressures between duals, loose or worn wheel
bearings, assembly non-uniformity such as improper bead seating and
out-of-balance condition, aggravated by high speed empty hauls.
TRAILER AXLE TIRES
EXAMPLE PHOTO & FIGURE
ACTION
TIRE
VEHICLE
OPERATIONS
If not worn excessively, continue to run. If wear is excessive, retread.
Diagnose mechanical problem and correct.
None
139
The Maintenance Council
2200 Mill Road
Alexandria, VA 22314
(703) 838-1763
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