Tire tread wearing can tell a lot about the suspension of your vehicle. It can also tell you whether the inflation, angles and components are all within specification. Following are the few most common patterns of tread wear and what can cause them.
- Over-inflated tires
If the tire tread wearing is noticed in center of tread pattern, then it will tell you that inflation patterns are quite high. Too much extra pressure may cause contact patch to shrink and tire center to carry the whole load.
2. Under-inflated tires
On the tire edges, if you notice tire tread is getting worn out then it will typically indicate that inflation pressures are much lower than what is specified.
In case a tire is little under-inflated, then the contact patch will grow and the whole load will be carried by its outside edges of patch.
3. Tire feathering
If there is excessive amount of negative or positive toe angle which is the indicator of tire scuffing or feathering, which can be easily detected by stroking the fingertips across each tread edge block or tread bar.
Any feather edge on inside of your tread bar will indicate that excess toe-in, while any feather edge on outside of your tread bar will indicate toe-out.
As toe angle will be affected by caster and camber angle changes and it is always last angle which has to be adjusted while the wheel alignment is going on.
In addition, if there is any change in caster or camber angles then it will immediately change toe angle. Also, toe angle geometry will be greatly affected due to changes in the suspension height.
4. Scalloped tires
Scalloped or cupped dips appearing all around the total surface of tire tread wear may indicate loose, bent or worn out suspension parts.
Unbalanced tires or worn shock absorbers may also cause cupping, however the cupping will typically be little more indicative of concentric pattern.
Struts and shocks are the most probable culprit because they will provide damping force for controlling tire movement. When tires will move excessively, then scalloped pattern may appear. Also, a lack of rotation may cause this condition.
5. Outer-edge tread wear
If the tread wear is noticed at the outer-edge of a tire which is very rare nowadays, but it can also happen sometimes.
Even positive camber, toe and caster can also lead to wearing on outer edge. In case if you see such edge wear only on one side, then check the thrust as well as setback.
However, it has to be noted that one of the leading causes of wearing at the outer edge on any modern vehicles can be over-enthusiastic cornering.
6. Inner-edge tread wear
This type of inner-edge tire tread wearing is the most commonly found tread wear problem that most technicians see. Various angles causing such type of wear can be typically negative toe or camber.
As far as parts are concerned, there are 3 component sources of inner-edge tread wear – springs, bushings and loads.