ONE-SIDED WEAR

APPEARANCE
Wear increasing from one side to the other.

PROBABLE CAUSE
Out of alignment specification parameters (camber, toe, axle parallelism).

CORRECTIVE ACTION
Check alignment and inspect for worn parts. 

TIRE DISPOSITION
Continue to run until minimum tread depth is reached.

SHOULDER STEP WEAR

APPEARANCE
Partial or full depression of the inside or outside shoulder tread rib.

PROBABLE CAUSE
This condition is common on radial tires in slow-wearing operations.

CORRECTIVE ACTION
None

TIRE DISPOSITION
Continue to run or rotate.

EROSION / RIVER WEAR

APPEARANCE
Circumferential worn area situated on the sides of the tread ribs.

PROBABLE CAUSE
Condition most commonly occurs on slow-wearing radial tires in steer or trailer position (free rolling).

CORRECTIVE ACTION
None

TIRE DISPOSITION
Continue to run.

DEPRESSION WEAR (INTERMEDIATE)

APPEARANCE
One or more interior ribs (not center) depressed more than adjacent ribs.

PROBABLE CAUSE
Incorrect air pressure, worn mechanical part, or nonuniformity such as mismount.

CORRECTIVE ACTION
Check air pressure and mechanical issues.

TIRE DISPOSITION
Rotate or retread.

DIAGONAL
WEAR

APPEARANCE
Manifests in the form of oblique wear patches. Can appear singularly or repeat around the circumference of the tire.

PROBABLE CAUSE
Misalignment, radial and lateral runout, severely out of balance, loose wheel bearings or steering parts.

CORRECTIVE ACTION
Check for mismount and worn parts.

TIRE DISPOSITION
Reverse direction of tire or retread.

MULTIPLE FLAT SPOTTING WEAR

APPEARANCE
Multiple radially worn areas around the tire.

PROBABLE CAUSE
Faulty shocks, loose/worn wheel bearings, severe balance issues, mismatched pressures or tire diameters, excessive high-speed empty operation.

CORRECTIVE ACTION
Check for mechanical issue; check air pressure.

TIRE DISPOSITION
Continue to run or retread.

FEATHERING

APPEARANCE
Feathering at the edge of the tread ribs.

PROBABLE CAUSE
Usually the result of continued exposure to lateral force, such as excessive toe. Can also form as a result of counter-steering to compensate for drive axle misalignment.

CORRECTIVE ACTION
Check alignment

TIRE DISPOSITION
Rotate to another position or retread.

DEPRESSION WEAR (SHOULDER)

APPEARANCE
Localized wear patch on the shoulder rib of the tire. This patch can repeat around the circumference of the tire.

PROBABLE CAUSE
Faulty shocks, lateral runout, loose wheel bearings, mismount, severe balance issue.

CORRECTIVE ACTION
Check for mechanical problem.

TIRE DISPOSITION
Continue to run, rotate or retread.

DEPRESSION WEAR (CENTER)

APPEARANCE
Circumferential depression wear of the center tread rib.

PROBABLE CAUSE
Overloaded/underinflated, faulty shocks, loose wheel bearings, mismount, high-speed empty haul conditions.

CORRECTIVE ACTION
Check air pressures/load weight and worn parts.

TIRE DISPOSITION
Continue to run, rotate or retread.

DEPRESSION WEAR (INTERMEDIATE)

APPEARANCE
One or more interior ribs (not center) worn below adjacent ribs around the tire's circumference.

PROBABLE CAUSE
Worn suspension components, mismatched dual diameter or inflation pressures, underinflation, improper bearing adjustment. Aggravated by high speed/light loads. 

CORRECTIVE ACTION
Diagnose mechanical condition and correct.

TIRE DISPOSITION
Continue to run until pull point, then retread.

DIAGONAL
WEAR

APPEARANCE
Localized flat spots worn diagonally across the tread, often repeating around the tire.

PROBABLE CAUSE
Improper bearing adjustment, misalignment, mismatched dual tire diameter and/or inflation pressure. May start as brake skid. Aggravated by high speed/light loads.

CORRECTIVE ACTION
Analyze cause and correct.

TIRE DISPOSITION
Reverse direction of rotation. If excessive, submit for retreading.

BRAKE SKID
DAMAGE

APPEARANCE
Localized spot of excessive wear across tread face showing abrasion marks. Damage may extend into casing.

PROBABLE CAUSE
New brakes (not worn in), unbalanced brake system, frozen brake lines, driver abuse.

CORRECTIVE ACTION
Check brake system.

TIRE DISPOSITION
May be repaired or retreaded if casing is undamaged; otherwise, scrap.

DEPRESSION WEAR (SHOULDER)

APPEARANCE
Localized areas of wear in shoulder, generally less than 12" in length.

PROBABLE CAUSE
Improper inflation pressure or tire mismounted on wheel. Can also be caused by some other type of wheel end imbalance.

CORRECTIVE ACTION
Review tire and wheel end maintenance practices.

TIRE DISPOSITION
Continue to run until pull point, then retread.

SHOULDER
STEP WEAR

APPEARANCE
Tire worn on edge of one shoulder, greater than 12" in circumference.

PROBABLE CAUSE
Excessive camber, misaligned or damaged axle, improper bearing adjustment.

CORRECTIVE ACTION
Diagnose misalignment and/or mechanical condition and correct.

TIRE DISPOSITION
Reverse direction of rotation. If excessive, submit for retreading.

CUPPING / SCALLOP WEAR

APPEARANCE
Random areas of fast wear around the tire. Erratic in some instances.

PROBABLE CAUSE
Mismatched inflation pressure or tire diameters in a dual assembly. Aggravated by high speeds/light loads, poorly maintained suspension components.

CORRECTIVE ACTION
Check for worn components, inflation pressures and matching tread depths.

TIRE DISPOSITION
Continue to run until pull point, then retread.