End of the Line

Identifying wheel end maintenance errors.


Fortunately for the technicians not involved in this year's competition, TMC wasn't the only group to discover a need for more clarification and training when it comes to wheel ends: manufacturers have become more consistent in offering solutions to deal with confusion amidst wheel end maintenance issues.

SKF Vehicle Service Market offers its Trouble Free Operations Program (TFO) in order to help fleets maintain consistent and successful service of their wheel ends. Initially, TFO advises a fleet on the proper seal relative to their particular application.

Depending on the duty, they may need one with a longer life seal to keep out contamination.

Leslie Kern, senior product manager, heavy duty market, SKF, describes the additional benefits of TFO: "Included with Trouble Free Operation is our training, and we find that to be very important for the technician," Kern says. "Our instruction includes the TMC Recommended Practices 618 bearing adjustment procedure and endplay reading. Achieving the proper bearing adjustment will go a long way in getting the longest service interval possible for a wheel end."


After TFO covers wheel end choice and maintenance, the program rounds out with a follow-up procedure, should a problem occur. "The TFO is a full circle program, and whenever there is a seal or bearing failure, we take that seal or bearing—with the customer—and diagnose what caused it to fail," Kern says.

"Very often it leaves evidence or ‘witness marks,' so you can see, maybe the wheel was installed cocked, or the bearing was subjected to heat which could be an over-tightened bearing adjustment. These are things to help reinforce to the installers the training that they've received up front. If they can see for themselves the effects of an improper installation, that helps reinforce the value of following the procedures that we recommend," she says. "It's important that the technician follow the proper installation and maintenance procedure, and the drivers do the required walk around the vehicle every time they get out."


Dana has taken the approach of designing a hub system that tries to bypass maintenance as much as possible. The Spicer® LMS™ (low maintenance system) is a pre-adjusted system which attempts to address several of the difficult elements behind wheel end consistency and longevity.

"Our LMS™ hub system included precision machine hub and spacer and premium bearings so that we could set the endplay properly every time in a wheel end," says Steve Slesinski, director of product planning for Dana's commercial vehicle systems. "By controlling that endplay, or pre-load, properly, it takes the adjustment out of setting wheel endplay. By controlling that endplay, it significantly improved the life of a good wheel seal."

Slesinski adds, "The next phase of improving the evolution of the wheel end was the venting system, where vents were developed to eliminate water from getting into the wheel end from either rain, flooding or high pressure spray." This led to an industry-wide adaptation of wheel ends to include venting systems to keep out water and, in the process, extend the life of the wheel end lubricant.

"We took that a step further with the LMS™ hub and hub cap by also putting an identification of the wheel end on the outside." The powder blue exterior is visible from across the garage, or even across the highway. "They're doing 70 miles an hour and the truck is coming at you, you can see it across the highway," Slesinski says. "If you're a maintenance manager and you have trucks parked in the yard and you want to know which you need to adjust, you could quickly see which ones."

Dana also offers a training program in the form of the Roadranger Field Service and Sales Organization.


Considering how tiny some of these parts are, the consequences of improper maintenance to a wheel end can be surprisingly disastrous and expensive. Leo Wenstrup, senior product manager for Dana's drive axles stresses the importance of using high quality, compatible lubricant for the system.

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