Irregular Wear

Shoulder Step/ Chamfer Wear

Appearance

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.

Probable Cause(s)

Typical of radial tyre in slow wearing operations. May vary with tread design and service application.

Tyre

Little or no loss in overall mileage will result provided tread depth differential is not excessive. Tyre can remain on the steer axle.

Vehicle

None

Operations

None.

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.

Tyre

If feather wear is severe, tyre can be rotated to another axle for maximum utilization of remaining tread.

Vehicle

Diagnose and correct misalignment condition as required. If feather wear on both steer tyre is in the same direction, drive axle or other chassis misalignment is indicated. If steer tyre feathers are in opposite directions, a toe condition is indicated.

Operations

None.

Cupping/ Scallop Wear

Appearance

Localized dished out areas of fast wear creating a scalloped appearance around tyre. Appears around the tyre 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.

Tyre

If ride complaints arise, tyre may be rotated to drive axle.

Vehicle

Diagnose imbalance condition, i.e., wheel, rim, hub, brake drum. Correct as necessary.

Operations

None.

One-Sided Wear

Appearance

Excessive wear on one side of tyre 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.

Tyre

Depending on severity of wear, tyre may be rotated to drive axle or, if worn to minimum tread depths on shoulder, submit for possible retreading.

Vehicle

Diagnose mechanical problem and correct.

Operations

None.

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.

Tyre

The tyre may be rotated to the outside drive dual position with change in rotation of the tyre. If wear is excessive, submit to retreader for further options.

Vehicle

Diagnose cause and correct.

Operations

None.

Rib Depression/ Punch Wear

Appearance

One or more inner ribs worn below the level of the adjacent ribs circumferentally around the tyre.

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.

Tyre

If not worn excessively, continue to run. If wear is excessive, retread.

Vehicle

Diagnose mechanical problem and correct.

Operations

None.

Heel/ Toe Wear

Appearance

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 tyre position on an axle.

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.

Tyre

If condition is not excessive, duals can be rematched to position flat spots 180° from each other. If more severe, the tyre can be repaired or retreaded if damage is not into the belts. If skid damage is into the tyre belts, it may be possible to remove the top belt and/or rebelt and then retread the tyre. Consult your retreader. If damage is excessive, scrap tyre.

Vehicle

Check brake material and brake balance.

Operations

Review driver training program.

Brake Skid/ Flat Spot Wear

Appearance

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 tyre in a dual assembly.

Probable Cause(s)

Brake skid occurs most often on dolly, trailer and drive tyre. 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.

Tyre

If condition is not excessive, duals can be rematched to position flat spots 180° from each other. If more severe, the tyre can be repaired or retreaded if damage is not into the belts. If skid damage is into the tyre belts, it may be possible to remove the top belt and/or rebelt the tyre. Consult your retreader. If damage is excessive, scrap tyre.

Vehicle

Check brake material and brake balance.

Operations

Review driver training program.

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 tyre sizes, worn wheel bearings, imbalance, air suspensions with bad shocks, driver abuse of trailer brakes; aggravated by high speed empty hauls.

Tyre

If not worn excessively, run tyre out. If remaining tread at worn spots is 2/32" or less, retread tyre.

Vehicle

Diagnose cause and correct.

Operations

Consult driver and review maintenance practices.

Rapid Shoulder Wear - One Shoulder

Appearance

Tyre worn on edge of one shoulder sometimes extending to inner ribs. Can progress to diagonal wipeout.

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.

Tyre

Change direction of rotation of tyre. If shoulder wear is severe, remove and retread.

Vehicle

Diagnose misalignment and/or mechanical condition and correct.

Operations

None.

Shoulder Scrubbing/ Scuffing

Appearance

Abrasion on upper tyre 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 tyre is hot. Most common on heavily loaded, spread axle trailers.

Tyre

Move affected shoulders to low scrub positions. If severe, tyre removal may be required. Inspect for serviceability on another axle or retread if possible.

Vehicle

None

Operations

None.

Tyre Information

Tyre Maintenance