For longer life of any construction vehicle — pickups, dumps, tool trucks, water trucks, or bobtails that haul heavy equipment such as dozers, excavators and the like — oil and lubricants could be the most important tools in your preventative maintenance program. Consider these comments from industry experts:

"Oil is looked upon as the lifeblood of your engine. Quality oil and lubes are essential for long-life in construction vehicles." — Ted Naman, technical coordinator, ConocoPhillips Company, Ponca City, Okla.

"One of the primary reasons for premature or catastrophic failure in construction trucks is the lack of lubrication or no lubrication." — Mark Betner, heavy-duty lubricants manager, Citgo Petroleum Corporation, Tulsa, Okla.

"Oil analysis is similar to taking a blood test to check your cholesterol. With oil analysis you're checking for dirt and other things that can kill a vehicle." — Joe Nixon, coordinator of services, ConocoPhillips, Houston, Texas.

And at Castol, Ian Fisher, laboratory manager, Baltimore, Md., remarks, "Although a percentage of contractors think oil is oil, there is a growing number, I believe, who view oil and lubricants as the lifeline of their equipment."

With this type of across-the-board endorsement, you'd think contractors would throw their full support behind such PM practices. But that's not necessarily so. For example, some construction fleet managers have become, if not exactly wary of oil analysis, then certainly apathetic toward it, according to Citgo's Betner. That apathy usually can be traced back to a bad experience, such as not having the right information going in, and thus not knowing what to expect from oil analysis and its results. "They may have taken a sample and it didn't tell them anything, only to have the truck fail two days later," Betner says. "Or, the flip side of that is they took a sample, it looked bad and they over-reacted and attempted to do a repair that wasn't necessary." Another factor in apathy, he notes, is cost. "Even if your oil provider says the analysis is free with your oil purchase," he says, "you have time caught up in mail, taking the sample, filling out the input data, and so forth. There's an investment on the contractor's end, too, and some contractors see it as something they can't afford." The trouble with that viewpoint, Betner says, is it's like saying you can't afford to go to the doctor, but you can afford a heart attack.

Obviously, an attitude adjustment among such contractors is needed and that comes through education and training, Betner believes. "Contractors shouldn't be afraid to ask the oil and lubricant supplier about the best practices to follow and about training the service technicians who maintain the trucks. Many times service technicians operate on perception, or on what they think is the right way to do the job," he says. "The supplier should teach them how to properly lubricate the chassis, know when there is not enough grease or too much grease. All these types of things are important to service technicians. And, when it comes to oil analysis, keep an open mind. Find out what its possibilities are," Betner says. "Don't rely on some past bad experience. That drives you into confusion."

To understand just how critical oils and lubes are to any PM function, you have to understand what they do, according to Castol's Ian Fisher. And, he says, they do a lot. The duties of oil, he explains, are to reduce frictional resistance, protect against corrosion and wear, contribute to engine cooling, assist in sealing, and make it easier to eliminate harmful combustion by-products.

"In a hostile work environment, extremes in temperature, long idle times, stop and go driving, and severe weather conditions put stress on the vehicle and the lubricant," Fisher says. That's why quality of oil and lubricants are important, he points out.

While the oil is being put through its paces, lubricants also are performing several functions within a gear, transmission or some other major component, according to Fisher. These functions vary slightly with regard to the specifics of a component, but the broad function of lubricants are to prevent metal-to-metal contact, prohibit wear, promote component efficiency, and provide protection against oil thickening during low temperature operation and oil thinning during high temperature operation.

Comments Fisher, "First, there is the environment. Dry, dusty conditions can cause contamination to invade the system. It is the lubricant's job to hold those contaminants in suspension, keep them away from critical components and not thicken excessively as a result of the contaminants."

When construction trucks and other worksite vehicles are operating in wet, rainy conditions, a lubricant must be hydrolytically stable — meaning it won't break down when contaminated by water. During extended high temperatures, Fisher says, the lubricant must be thermally stable — that is, able to withstand heat without losing viscosity or shearing out of grade, which would subject the component to wear.

Any contractor foolish enough to ignore either oil or lubes as PM tools is taking what could be very costly risks. Ignore the oil, says Fisher, and the vehicle will experience wear, deposit formation and oil consumption, all leading to catastrophic engine failure.

Ignore lubricants, he adds, and excessive wear will result, shortening component life, reducing vehicle efficiency and ultimately causing vehicle downtime. And don't ignore recommended drain intervals, cautions Ted Namen at ConocoPhillips. "If oil drain intervals are ignored during regular, ongoing PM, you'll see in the oil analysis report a higher level of wear metal in the oil," he says. "That means wear is taking place inside the engine. This usually is accompanied by a high level of silicon in the oil and that comes from dirt," Naman says.

Maintaining the oil's cleanliness is critical, he comments. "What I mean by this is that the air filtration has to be properly maintained because if dirt gets into the engine — and operating off-road gives you plenty of dirt to get in — the air filter has to function extremely well," he comments. "Most air filtration systems have indicators on them, which tells the contractor when the air filter should be changed, or when it becomes restricted. Just as important, too, is the oil filter and, as I said, don't extend the recommended drain intervals."

In addition to component lubrication and engine oil, Naman says there are other areas to keep an eye on, such as the hydraulics system. "It is even more critical to maintain the cleanliness of hydraulic systems because they operate at much higher pressures than engine oils," he points out. "On-board hydraulic pumps — no matter if they are on haul trucks, excavators or front-end loaders — usually operate between 3,000-psi and 5,000-psi pressure in the hydraulic system. When you have hydraulic oil circulating at these high pressures, it's essential that the hydraulic oil remain clean and filtered accordingly. The slightest amount of dirt that gets in there aggravates the system."

By contrast, greases are more forgiving, according to Naman. Yet here, too, there are certain recommendations that shouldn't be ignored. "There are different types of thick nesses in grease," Naman explains. "The most common are lithium and lithium complex. The differences between the two types are that lithium complex can stand higher operating temperatures that lithium grease. It uses an entirely different thickener to withstand higher temperatures. What you find is that the heavy-duty equipment manufacturers will call for lithium complex grease with moly in it. Moly has a grayish, black color and acts as a friction reducer as well. It's also a cushion under shock load conditions," Naman says. "There's not a whole lot a contractor can do here except follow the greasing intervals and that's based on hours. Usually greasing is done when brakes are inspected."

As for gear oils used in the differential housing, among other places, the most common type is called API Service GL-5. Although this is the most common type, Naman says more and more companies are turning to synthetic gear oils because they hold up very well and allow the equipment to have an extended service life. Says Naman, "If the contractor lets the equipment go a little longer before servicing it, the synthetic provides a bit of a cushion."

In looking at the broader picture, Mark Betner at Citgo identifies three things that have an impact on lubrication-related engine failures — the fueling system, air filtration system and the cooling system. "All three can contribute to oil contamination which can lead to premature, catastrophic failures," he says. "The fueling system — if the fuel injectors aren't properly maintained — can lead to engine deposits and fuel dilution, both of which can cause engine failure. The air induction system by itself can be a limiting factor in oil drain interval capability. The cooling system, by not maintaining the coolant and by losing coolant integrity, could lead to deterioration of the engine itself and contamination of the oil." He adds, "All these systems problems are the pathway to death."

Oils and lubes might appear at first glimpse to be simple tools in a contractor's PM program, but the roles they play are complex and interwoven with the functions of the vehicle's other components. To stay out of trouble, here are a few guidelines and tips to follow:

Always use high quality products, preferably the most recent, technically advanced, that exceed industry specifications and field tests. As an interesting aside, the experts say smaller, independent companies are more quality conscious about what goes into their construction trucks than nationally operated, large fleets. Big fleets often are more price conscious, they say. Whatever size fleet, make sure you keep up with the latest developments in lubricants. Don't just rely on past understandings. There have been more developments in the last decade than in the first 30 years leading up to that decade.

Know your fleet operating conditions. Do you have severe loads outside the box — that is, more load than the truck is designed for? Is there excessive engine idle time? Is the severity of your operation such that your fuel consumption is higher than what is considered normal for that engine?

Follow maintenance recommendations for servicing the vehicle.

And finally, if you don't have a monitored maintenance program in place, then get one — and do it right away.