Tire tread separation is a potentially dangerous condition wherein the tread of the tire separates itself from the casing or body of the tire. Most all of the tires made for the cars, light trucks, mini vans and SUVs that we drive today are steel belted radial tires. The most common defect in steel belted radial tires is tire tread separation.
One of the most common complaints or problems that drivers have in regard to their tires is that they notice that the car shakes at a certain speed. Any vibration that feels like a lateral, or side to side shake which is most noticeable between 10 and 40 miles per hour is a problem with a tire, rather than a problem with a wheel.
Tires are made of specialized rubber compounds and are reinforced by plies of fabric cords and metal wires. While most rubber compounds can be stretched easily, it is the underlying fabric cords and steel wires that actually determine the shape of the tire by restricting stretching. In order to bond these different materials together, the cords and wires are coated with adhesives and/or rubber before the other components are bonded to them during curing.
A strong bond between these different components is required to provide the desired durability. The strength of the bond can be reduced by several different factors.
1. Manufacturer’s Defect – Even though the numbers are quite low, tire manufacturing defect is actually one of the most common causes of tread separation. Something went wrong in the chemical processes during manufacturing and the tread and steel belting section didn’t properly bond to the tire casing properly. Over time, and usually not a long period of time, a defective tire will begin to exhibit signs of an extreme out-of-balance condition. Ultimately, a bump will form in the tread area. This bump is the first visual indicator that the tread is going to separate. The expansion of this bubble will increase until a tire failure occurs. As soon as you notice an abnormal vibration you should inspect your tires both visually and by touch looking for.
2. Tire Abuse
- Over inflation of the tire, especially on rough roads. Excessive air pressures can cause excessive heat generation, accelerated wear and also doesn’t allow the tire to absorb road shocks. Especially from potholes.
- Careless driving habits – Potholes are the worst enemies a car’s suspension and tires have. Tires are designed to absorb the shock derived from impact, with smaller potholes at driving speeds and larger ones at slower speeds. However, if you hit a good sized pothole at or just below freeway speeds, you can generate enough force to cause a tread separation.
3. Incorrect Flat Repair – The most reliable and effective method of repairing tire punctures is by using a combination of radial patch and plug. If the puncture is not properly prepared prior to plug/patch placement, the tip of the plug portion can cause a tread separation to begin. Once tread separation starts, there is no correcting it. It will spread until the tire must be replaced.
4. Excessive Tire Wear – Tires are designed to deliver a set number of miles before they must be replaced. Once you’ve reached the end of a tire’s life, tire blowouts, tread separation and loss of traction can occur. If you have reached the rated mileage for your tires, they should be replaced to prevent serious problems.
How to determine if you have a tire that is separating.
If you think you have a tire that is separating, it will be necessary to inspect the tire while mounted on the wheel. Many times you will notice impact damage on the wheel adjacent to a separation/bubble. You will also be well advised to have the tire dismounted in order to inspect the condition of its inner liner.
With the tire lifted off the ground and the tire turning, stand directly behind or in front of the tire and watch the tread to determine if there is a lateral shift from side to side in one specific area. It is fairly easy to spot, as the tread lines should remain straight as you turn the tire.
If you notice a wavy pattern in a particular spot, you found your problem. This is a tread separation. You should also look for obvious things, such as high spots or bumps indicating a separation due to an impact or defect in the tire. Look at both sidewalls of the tire. If no irregularities are present, then proceed to the next tire until you locate the culprit.
While taller profile tires can be damaged by the severe impacts with deep potholes and sharp curbs, low profile tires mounted on large diameter wheels are the most vulnerable to this type of damage therefore, drivers of vehicles equipped with low profile tires should pay special attention to avoid potholes, curbs or other road hazards.
Once again, a separated tire is a potentially dangerous situation since the tire will eventually either go flat or the tread will come off while the car is in motion. Obviously, this could cause considerable damage or an accident. The only remedy for a tire separation is to replace the tire.