A trucking company is only as good as its tires. Here at the QuickTSI blog, we spend a lot of time talking about tires. Why do we do that? Because the trucking industry transport 70% of all the nation’s freight on tires. Without them, none of this would be possible. Commerce would be impossible. That’s why we want to talk more about how to properly evaluate your fleets’ tires so that you aren’t spinning your wheels and wasting money.
A tire expert often can tell what’s happening to a tire by just looking at it or rubbing a hand over the tread face. They know. Why? Because tire wear usually isn’t the tire’s fault. There’s something wrong with the truck that’s aggravating the situation. You must fix that problem to prevent the tire wear. So where do you start? And what do you do with the information you gather?
Be Careful as You Conduct Your Analysis
Tire wear is often viewed as the problem. In fact, it’s just a symptom. Various mechanical problems leave signature wear patterns on a tire. The solution is not to replace the tire, but to remedy the cause of the irregular wear. You don’t want to throw away a perfectly good tire.
The ATA Technology & Maintenance Council’s Recommended Practice 219C illustrates more than 30 common wear patterns and lists likely causes. A single mechanical problem can produce several different types of wear, and sometimes when two or more mechanical defects are present, the wear patterns can become misleading. It is the tire technician’s job to understand the difference.
For instance, wear that appears on steer tires may have nothing to do with the front end of the truck. One should never be quick to jump to conclusions. Drive axle misalignment may show up on steer tires as shoulder wear, but on the same sides of both steer tires – inner shoulder wear on one tire, outer shoulder wear on the opposite tire. This is caused by the steer tires countering an off-center push from the crooked drive axles.
A Closer Look at the Different Types of Tire Damage
Let’s look first at some common self-inflicted tire damage. This type of damage is the type that refers to wear not directly related to mechanical defects on the vehicle.
First, there is inflation-related damage. Shoulder wear, center wear, and excessive cupping and scalloping are common symptoms of inflation-related tire wear. These symptoms can appear on tires at all wheel positions and could be confused with wear caused by several other factors. Mismatched inflation pressures in adjacent dual tires are common problems that yield similar results. A simple inflation pressure check will tell if a problem exists. These are simple problems in the world of a trucking company tire technician.
Next, we have load and pavement-related damage. Roads and loads all have an impact on tires as well, and each will leave its own unique mark on your tires. The difference in road crowns and pavement texture will affect tire wear, and if trucks spend a lot of time on less-than-ideal road surfaces, the wear could be accelerated.
Make sure you spec tires for their intended application and re-evaluate your decision if tires show unexpected wear. Certain applications, such as liquid loads, can contribute to rim flange wear, which can lead to bead damage. And you don’t want that. Loads with high centers of gravity are more likely to sway, which can cause excessive loading on tire shoulders leading to edge wear.
Installation and Truck Driver Related Damage
Improper installation is a problem when the technician makes a mistake. And mistakes happen. One shouldn’t be too hard on themselves after making a mistake. Among the wheel-end-specific problems associated with irregular wear are improper tire mounting or non-concentric mounting. This could include radial or lateral run out, loose wheel bearings and worn wheel mounting studs.
Any tire that is not running true will quickly exhibit signature signs of wear. Mixing different brands and models of casings in a dual assembly also encourages irregular wear, as they may not have the same rate of sidewall flex. This will change the circumference of the two tires, which will put additional stress on the stiffer tire and may cause scuffing wear on the softer tire. So, above all, make sure you use consistent tire brands and casings.
Next, you must take truck driver-related damage into account. Aggressive truck driving habits, such as hard braking, high-speed driving and cornering will affect tires too. All these factors will stress the shoulders of the tires, and wear may appear as flattening or smoothing of the shoulders. This might be not unlike the wear caused by improper camber or misalignment. Sidewall damage to the right-rear-outside trailer tires is likely caused by curb strikes. Some damage is inevitable, but willful neglect should be properly dealt with.
Finally, consider light or empty operation. Fleets that run diminishing loads or empty a large part of the time, such as petroleum or milk haulers, experience rapid tire wear due to the light loads on the fully inflated tires. Under load, contact with the pavement is even across the tread face, but when empty at normal operating pressure, the center of the tread tends to be slightly higher than the shoulder.
Mechanical Problems Associated with Premature Tire Wear
Common mechanical problems associated with premature tire wear include misalignment of any axle on the truck, poorly maintained suspension. This could also be badly maintained steering components, loose, bent, or broken suspension components and shock absorbers.
Issues like irregular tire wear can offer glimpses into a fleet’s tire maintenance practices. Do you want to be the one that stands out because your tires keep failing inspections? For example, too many tires with big differences between the wear on one side of the tread compared to the other could indicate that alignment issues are not being addressed.
Mismatched duals should be avoided at all costs. Indeed, mismatching your duals can be outright dangerous. The two outer tires appear to be in decent shape, but they are taller than their inner counterparts.
Additionally, the sidewall flex characteristics of the two pairs of tires are probably different. The upper left tire looks like a vocational model, while the tire on the lower left has suffered excessive shoulder wear at a previous steer-axle wheel position, probably caused by improper camber or drive axle misalignment.
The key lies in detecting these problems early. When detected early, there’s a good chance the tire can be salvaged by moving it to a different wheel position. Let go too long, the tire might wind up in the scrap pile. And any tire that winds up in the scrap pile is a hit to your bottom line.
Don’t Hesitate to Analyze Your Scrap Pile
Unfortunately, scrap piles happen. Thousands of tires are scrapped prematurely every month in the United States. That’s hundreds of thousands of miles of operation fleets give up because their tires died untimely, unnatural, and often unnecessary deaths. And the tires themselves are rarely to blame. The key is to get to know your scrap pile.
Take a walk through your scrap pile and study what has caused your tires to fail. You’re bound to find shoulder wear, feathering, cupping, scalloping, punch wear, zippers and more. Scrap tire analysis can help tell fleets what is working and what’s not. Scrap tire analysis can also help fleets choose the best tires for their applications, routes, and environments. In the transportation business, knowledge is power, and there is a tremendous amount of knowledge sitting in a scrap tire pile. You just must know where to start.
Start by establishing a tracking program. You need to identify which truck and wheel position the tire came from, so problems can be traced back to the source. Tire management tools available in many maintenance apps make this much less time-consuming, but even if you are using only a basic spreadsheet or even pencil and paper, the insight you can gain from the analysis can save your fleet a fortune.
The tracking mechanism can be as elaborate or simple as necessary and will vary with fleet size and with the maintenance department’s ability to track the data. It often comes down to a combination of factors that include tire construction, tread design and compounding, the steering geometry and suspension characteristics of particular vehicles – and even the truck’s work environment. Identifying the wheel position as well as the unit number and its application will provide a better picture of the service the tire saw.