Commentary: Determining proper service interval frequency is a balancing act

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Updated Apr 22, 2020

While there’s a lot of hype over predicative maintenance these days, we can’t afford to take our focus away from basic preventive maintenance and service intervals. Determining proper service intervals frequency is a balancing act.

Joe Puff is vice president of truck technology and maintenance for NationaLease.Joe Puff is vice president of truck technology and maintenance for NationaLease.

On one side, we want to keep things standardized to ease the challenges of doing business. On the other, there are a lot of savings for conducting unit and component services just in time. Oil drain intervals, for example. A certain 2016 15-liter engine might have an OEM recommended oil drain interval of 25,000 miles for severe-duty applications, 35,000 miles for short haul and 50,000 miles for long haul.

That same OEM’s 2018 engine may have oil intervals at 35,000 miles for severe duty, 45,000 miles for short haul, 60,000 miles for long haul, and 75,000 miles for efficient long haul. In addition, that same OEM’s 13-liter engine could have yet another set of published intervals. That’s just one manufacturer.

Imagine the challenge of setting and tracking oil drain intervals for a heterogeneous fleet of a variety of Cummins, Detroit, Volvo, and Paccar engines with varying model years and varying engine sizes.

With all these variable, here is what you need to consider in order to set oil drain intervals:

  • OEM recommendations
  • Idle time
  • Fuel mileage
  • Duty cycles
  • Environmental impact
  • Oil analysis

Now that you have all of the variables, you need to determine a strategy:

  • Do you simplify the fleet’s oil intervals by using the shortest OEM recommendation and set the entire fleet to that interval?
  • Do you manage it vehicle-by-vehicle? It may take a fair amount of effort to manage it unit-by-unit, but it can afford huge savings.

You can apply the same scheduling logic for setting intervals for various other component PM items such as air dryer cartridge replacement, cabin air filters, DPFs and engine air filters. Remember, you will have to select variables that make sense for each component.

For example, air dryer cartridges need to be replaced more often in humid climates such as Louisiana, Alabama and Florida, especially when these units are operating in an urban environment where air demands are higher. A unit domiciled in a humid climate but operating in regional or long haul may not need the cartridge replaced as frequently as the vehicle used in an urban environment.

The key to setting intervals is to evaluate each unit’s application and set PM and component maintenance intervals for that specific vehicle spec and unit’s application.

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But whatever you do with maintenance intervals, don’t exceed the OEM’s recommendation.

Joe Puff has more than 35 years of experience in complex sales and fleet operations, including extensive experience in commercial vehicle maintenance. He is responsible for advising NationaLease members and the National Account team of new truck technology, industry trends, and maintenance best practices.