For those who are concerned with the liability associated with wheel installation, the evidence left behind is an easy “smoking gun” for the plaintiff’s attorney looking for the cause of a wheel-off accident. None of the wheel, hub or fastener manufacturers recommend the use of any lubricant on a stud-piloted wheel system other than oil, so residue left by anti-seize compounds becomes an easy scapegoat for even the most inexperienced attorney.
On the other hand, the use of oil on a hub-piloted installation is crucial to the torque and clamping force relationship.
While there may be some lack of consensus on the use of lubricants for stud-piloted wheel systems, all of the manufacturers and industry organizations agree that standard 30-weight motor oil must be applied to the studs and flange nuts before installing a hub-piloted wheel. In fact, when oil is not applied, or anti-seize is used as a substitute, the recommended torque can result in up to a 50 percent loss of clamping force.
So, fleets that are diligent in their efforts to ensure that every hub-piloted wheel is installed with the proper torque could be creating additional problems if the studs and flange nuts are not properly lubricated. It becomes a perfect example of the phrase: “false sense of security.”
TIA’s Fleet Tire Service OSHA Compliance Training Program details the relationship between torque and clamping force on the three main wheel and rim systems used in North America.
The hub-piloted fastener tests alone are usually enough to convince even the most experienced technician that there might be a better way. If that doesn’t do it, then the footage of a wheel-off striking a parked car makes a believer out of most students.
Truck rim and wheel systems are a lot more than just nuts and bolts. Without a firm understanding of how these systems work and the role that a lubricant plays in creating clamping force, technicians are simply guessing every time they install a wheel or rim.