Whether it’s mismatched or damaged by overloading, the release of the pressure from the clamps is enough to allow the components to separate. If tires are completely deflated before the lug nuts are loosened, there is no risk of a separation during the removal process.
On the other hand, if fully inflated multi-piece assemblies are removed from the cast spoke wheel, there’s always a chance that a fatal or serious accident can occur.
Nothing really changes for the Tube-Type Chart. We just want to remind everyone that people are still getting injured or killed when loosening the lug nuts on these assemblies when they are inflated.
Rim Matching Chart
The most obvious change to the Multi-Piece Rim Matching Chart is the structure. In the old chart, the out-of-production parts were listed along with the current production so it was easier to make a mistake.
Under the new format, there is a clear difference between the two, and the word “obsolete” was added to encourage technicians to take a closer look at components with those identification stamps.
In many instances, the components will be 30 to 40 years old and completely unpredictable from a strength of materials standpoint. They are not “illegal,” but they are obsolete and best suited for scrap and eventual recycling.
For the Demounting and Mounting Procedures for Tubeless Truck and Bus Tires chart, problems like zipper ruptures and heat damage to disc wheels are addressed.
It is important to make sure that all technicians are aware of the signs of a potential zipper rupture so they can recognize it during inspection or inflation.
While the new tubeless chart doesn’t mention overinflation as part of the zipper rupture inspection, it still includes all of the basic principles for demounting, mounting and inflating tubeless tires on single-piece rims, and includes new information on inspection and rim identification.
The Overinflation Step
Be advised, the Rubber Manufacturers Association (RMA) recommends overinflation, and TIA agrees.
Every steel radial truck tire that is returning to service must be overinflated in the restraining device to test for a zipper rupture. We’ve seen them zipper without warning during the overinflation step of the process, so we know that inflating to the recommended pressure may not be enough.
Thankfully, tires never zippered during the old 20-minute waiting period, which is why it went away, but the overinflation stayed. If the tire doesn’t zipper after the stress of overinflation while contained in the restraining device, chances are good it won’t happen during installation.
For a free copy of the RMA Tire Information Service Bulletin, visit www.rma.org/publications/tire_service_professionals/index.cfm?PublicationID=11514.
Know the Risks
None of the information on the three OSHA charts should be new to the tire or trucking industries. Unfortunately, there are still people being seriously injured or killed because they are unaware of the risks associated with servicing truck tires and wheels.
The new OSHA charts should better help technicians identify a problem before someone gets hurt.
The OSHA standard mandates training for everyone that touches a truck tire and these charts should be an integral part of every training program.
The Tire Industry Association (TIA) is an international association representing all segments of the tire industry, including those that manufacture, repair, recycle, sell, service or use new or retreaded tires, and also those suppliers or individuals who furnish equipment, material or services to the industry. TIA was formed by the July 2002 merger of the International Tire & Rubber Association (ITRA) and the Tire Association of North America (TANA). TIA’s main office is in Bowie, MD. The association has more than 6,000 current members.