Applications and Innovations
Better Roads Staff | July 7, 2011
Service intervals are not ‘one size fits all’ routines
Today’s fleet and service managers have a lot of responsibility riding on their shoulders, as they balance productivity with costs of operation. Vehicles and equipment in the shop for repairs are expected, but they hurt the bottom line.
That’s why preventive maintenance is so critical to controlling operational costs. The big question, however, is how often should the pickups in your fleet be serviced? Do you follow the vehicle owner’s manual or set up your own system?
The answers are not cut and dry. What works for one company or agency may not be right for another.
For example, do you know which battery to connect to when you jump-start a 6.7L Power Stroke, what coolant is required for the Hybrid Silverado/Sierra’s control module, or which eight of the Ram 4.7’s 16 spark plugs are changed more frequently?
Vehicle owner’s manuals and supplements may not be the most exciting prose, but they do provide valuable service information – including definitions of “severe service” and listed maintenance schedules.
Most new pickup service intervals specify a limit between oil changes of 3,000 miles in severe service and up to 8,000 with easy use. The typical fleet pickup usually falls into the severe-service category.
But most also have built-in oil minders that use drivetrain sensors and determine the interval for you; a “change oil” message on the dash display pops up reminding the driver an oil/filter change should be completed within 500 miles.
Bear in mind these electronic minders don’t sample the oil. They monitor heat, oil level and a lot of other parameters to determine what percentage of oil life remains before letting you know it’s time for a service.
Also, they may not track engine run time, and a truck that sits idling for long periods of time may need fresh oil even if the minder doesn’t say so. Relying on the minder is a poor excuse for not pulling the dipstick while refueling.
Extending oil drain cycles beyond 8,000 miles, even with synthetics and oil sampling, isn’t a good idea, either. No one we consulted makes that recommendation for newer diesels (anything built after Jan. 1, 2007) because of the effects of emission control and changes to the required oil specification.
Synthetic oils may still be used to maximize the extreme lubrication protection in cold and heat, but running them longer jeopardizes the engine warranty.
Regular oil analysis is still the best way to determine when the oil and filters need to be changed in individual pickups. Consult with your oil analysis lab on how to set up a baseline for each vehicle, the analysis frequency and how to read the results.
Those results will tell you when the next oil service is needed, and keep you aware of wear issues that may be brewing inside the engine.
Periodic and recorded service is the simplest, most cost-effective way to keep your truck running reliably, maintain the warranty coverage and preserve resale value. And regular cleaning makes life easier on drivers and identifies problems earlier.
With no-maintenance electronics playing an ever-larger role in the operation of late-model pickups, most routine service boils down to lubricants, filters, brakes and tires.
A decent service log, backed up daily, is the easiest way to ensure your truck gets attention when needed. This can be as detailed as fleet maintenance software, a good relationship with your dealer’s service department, a laptop spreadsheet or notebook, and a file cabinet.
Date, odometer miles, work performed, receipts with part numbers and a notation on the calendar approximating the next time service is due is the minimum; your accountant or mechanic may recommend more. And if you’re forgetful or lazy, you need an effective reminder system.
Engine oil doesn’t really wear out. The additive package added to the base oil stocks (detergents, anti-foaming agents, etc.) wears out, and contaminants get in the oil.
In newer diesels with diesel particulate filters (DPF) extra fuel is occasionally injected to “regenerate” the DPF and since it’s done after the combustion event, some fuel inevitably washes down the cylinder walls and dilutes the oil no matter what kind of oil it is. (The 2011 Duramax has a ninth injector in the exhaust system that helps alleviate this issue.)
That fuel dilution is a primary reason you can’t extend the change interval on new diesels: True, you could do frequent analysis for fuel dilution, but the time and money spent on the synthetics and analysis would buy a conventional oil change anyway, so you’re not saving anything.
Unless you’re improperly using the truck outside its design parameters – or in extreme climates – do a cost/benefit analysis before choosing a synthetic engine oil in any new pickup.
Also note that in the long run — this is why you document — pushing a service interval to the recommended oil change may not pay off overall.
One large fleet manager we spoke to in Los Angeles found the 6,000- or 7,500-mile intervals in the book were fine for engine oil. But those miles were too far for the physical inspection that accompanies routine service, so any savings in oil service were more than offset by brake and other repairs not caught sooner.
While manuals are thorough, service managers and pickup owners should never pass up a chance to ensure the cooling stack is clean and lug nuts torqued on all the wheels – including those on the trailer.
What to Use
Your manufacturer specifies fluids, and most oils have an American Petroleum Institute identifier with the classification and viscosity (e.g., API CJ-4 5W-40).
Synthetic lubes are approved, although many experts we consulted advised such lubes should not be used (unless factory-filled) for the first 5,000-10,000 miles to ensure proper piston ring seating.
Synthetic lubricants are especially beneficial in severe climates. For example, the 2011 Ram diesel manual dictates 5W-40 synthetic oil for operation at zero degrees F or lower.
Note also that fluid ratings are not always “backward-compatible.” In other words, newer is not always better despite petroleum industry assurances. A manual gearbox that calls for GL-4 will not last longer on GL-5; in fact, some parts will wear quicker.
All brake fluids comply with Federal standards but DOT 3, DOT 4 and DOT 5 are not newer and better (5 is silicone-based, 5.1 is not). Engine oils are API-classed S for gasoline engines and C for diesel.
The newest diesel oil standard is CJ-4. Some long-term diesel owners have found the CJ-4 for ULSD/DPF engines doesn’t have the same levels of zinc, phosphorous and detergents, and is not as good as the CI-4 Plus that preceded it. Many oil companies don’t want to produce two oils, but if you can find it, CI-4 Plus is often regarded as better for pre-DPF-era diesels.
If your truck requires any additives, like those for limited-slip differentials coolants in earlier Power Strokes or some fuel stabilizing agents, the owner’s manual will says so. Otherwise, forget additives and put that money to better use doing routine service.
Almost every lubricated component has some sort of filtering device, from a magnetic drain plug to fuel filters. These are cheap insurance when the proper parts are changed at recommended intervals or during an associated repair.
In those cases where truck and engine come from different manufacturers (e.g., Cummins/Dodge, International/Ford) an engine company’s service provider may have better prices and parts availability.
“Proper” part refers to that named acceptable by the manufacturer (engine or truck); more than one diesel pickup owner has suffered an engine failure because the media from an aftermarket oil filter broke off and plugged a piston cooling jet, and warranty coverage was denied.
If a factory filter is $15, a cheap one $8, and an engine $10,000, which is the best value?
Two other parameters deserve careful consideration: clutch-pack limited-slip differentials and diesel fuel filters.
Fuel filters on newer diesel engines are critical. With pressures more than 20,000 psi, even the smallest contaminant can do damage (think what your pressure washer does at one-tenth that pressure), and parts are not cheap.
The thousandths-of-an-inch clearance in a crank bearing is huge compared to the tolerance in diesel injection, where writing on a part with a Sharpie means it won’t fit anymore. If you’re a do-it-yourselfer, don’t pre-fill a diesel fuel filter because your eye can’t see contaminants that could cause damage.
Limited-slips improve traction and are an inexpensive factory option considering the traction advantage over an open-diff. Nearly all of them require periodic service and an additive to work correctly. Forget the additive and they eventually become unlimited-slips.
This article was written by G.R. Whale, a contributor to our sister publication ProPickup magazine
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