I recently received a question from a Fleet Owner reader who inquired about the need for balancing truck tire and wheel assemblies. Since I can neither endorse nor discourage the use of a product or practice, answering the question directly is virtually impossible. But I can provide some basic information that should help everyone achieve a better understanding of why it's an issue.
Before we even discuss the attachment of lead weight to the rim flange or the installation of an internal compound, a properly mounted, seated and inflated assembly is a must. Tire lubricant (not dish soap) must be applied to the beads and the rim prior to mounting and the beads should be seated with the tire lying flat so it is parallel with the ground. Proper inflation will also have an impact on balance, so the pressure must be set to carry the load.
A quick walk around the yard will tell you if the tires on your equipment are seated correctly. Every truck tire has a rubber rib or ring that runs around the circumference of the sidewall just a few millimeters above the rim flange. If the distance between the rim flange and the rubber rib/ring varies by more than 2/32 of an inch (or at all), the tire is not properly seated and it may cause a vibration and/or irregular tread wear.
Another sign of an improperly mounted tire is an alignment dot that is not aligned. Some manufacturers use a yellow or red dot to identify the spot on the tire that should be aligned with the valve stem or the dimple on a steel rim. If the yellow and red dots on your tires are all over the place, the person responsible for mounting and inflating your tires could also be contributing to ride complaints from drivers.
While we're on the subject of drivers, I remember a school bus fleet that had a driver who was never happy. After messing around with different tires and rim re-alignment procedures (they were spoke wheels), I proposed we strobe balance the steer tires on the bus. To make a long story short, the driver was so happy with the result that the rest of the fleet suddenly had vibrations we needed to solve. I was a hero in the drivers' lounge, but the maintenance manager nearly choked me after he saw the $1,000 tab for 20 buses and I told him the tires would need to be rebalanced after every removal.
There are definite benefits to a balanced truck tire and wheel assembly. I've spoken with people who have provided testimonials and I've seen most popular approaches work in certain applications. A smoother ride means less wear and tear on the driver and the suspension, not to mention improved tread mileage. Reputable manufacturers of balancing equipment and products have a plethora of factual data that proves their process resulted in better performance. If they don't have any data, be very cautious.
But I also recognize that tires are a major operating expense and unless it can be said that spending extra money on balancing results in bottom line savings, some fleets are probably going to pass. And since there's no guaranteed return on the investment, any balancing program must be approached with a constant eye on the economics. But if tires are properly mounted, aligned, seated and inflated in the first place, the extra cost may not be necessary. In fact, concentrically seated radial truck tires on aluminum wheels are so close to balanced that most drivers couldn't tell the difference.