Some Slippery Basics

The environment inside the engine and hydraulic and power systems of the typical loader, bulldozer, or motor scraper can be intensive. Physical forces from the compression and expansion of hot gases from combustion thrust different types of metals against each other. External temperatures ranging from the freezing winters of the Great Plains to the hot climates of the Sonoran Desert of the Southwest mean that the external surfaces of the power plant may be subzero while the internal temperatures are hot enough to boil water. Differences in thermal expansion in components increase friction and component wear. Hydraulically controlled blades or buckets twist and torque from the sudden impact with a recalcitrant boulder, causing the system's pressure to spike. Gear trains grind under overweight loads in uneven terrain.

On the typical piece of heavy equipment there are six principal systems that require a fluid or lubricant. The first is the engine lubricating system, comprising a reserve of crankcase oil and a pumping system that distributes the oil to the internal parts of the engine. The second is the cooling system that is designed to remove excessive heat from the engine and vent this heat externally through a radiator and fan system. The third is the transmission or gear-train system, which is designed to reduce the frictional wear of the gear system while providing cooling functions. Depending on the type of equipment, the gear-train system may consist of additional independent systems that separately control the drive wheels. The fourth is the braking system, consisting of both mechanical and hydraulic components. The fifth is the hydraulic system that usually consists of a pump, reservoir, and cylinders that control the movement of blades, arms, or other parts. The sixth is the grease system, the multiple locations on a piece of heavy equipment in which grease is inserted to reduce wear. These points will be found at any location where two components move against each other.

While the number of different products and brands of fluids and lubricants can range in the thousands, they can be broken down into three basic families: petroleum-based, synthetic, and biodegradable. Petroleum-based products are those derived from crude oil and formulated into various products through the refining and distillation processes. These products have historically been the primary choice and occupy the largest market segment. Through research and development, petroleum-based products have been custom-tailored to meet specific operating conditions and equipment specifications. If you need a specific lubricant for use in a certain model backhoe that's going to be digging trenches in the damp marshes of the tropics, chances are that product exists.

Synthetics are chemically engineered products that offer the same characteristics and functions as petroleum-based products. According to David Anderson, director of technical sales for Amsoil Inc. in Superior, WI, synthetics have a greater life expectancy and operational range. "Synthetics have the ability to function in an application for a longer period of time and over a much broader temperature range, allowing the same fluid that's used in Alaska to be used in Florida."

The biodegradable products are relatively new to the market and are primarily derived from vegetable-based material. Biodegradable lubricants can be particularly useful in ecologically sensitive environments where a hydraulic spill would have severe environmental consequences. Biodegradables are somewhat restricted in their applicability and, as a result of limited operational life, are often more expensive than petroleum or synthetic products.

If you own a large quantity of different types of equipment, will the same crankcase oil, grease or hydraulic fluid be right for each one?

Petroleum-based products have traditionally been solvent-refined---the solvents are used to extract impurities in the crude. Recent advances in refinement have resulted in a new technology to extract impurities called "hydrocracking." It's a chemical conversion process that reconfigures the petroleum molecules and tailors them to the desired viscosity. According to Roger Leveque, marketing manager for lubricants with Conoco Inc. in Houston, TX, "With hydrocracking you end up with a product that is colorless, odorless, and, in fact, tasteless. All the impurities are removed through alteration of the structure of the original material." Because this process converts the material itself, there are no disposable extracts either. "You essentially recover all the material. The result is a very-high-performance product that can be tailored to specific applications. It is much more stable and has a longer application life; we like to say that we sell uptime," says Leveque.

Adding Additives

While the most obvious function of any lubricant is to reduce friction between moving parts, that is not its only purpose. In addition to lubricating, oil must also clean, cool, and seal in an engine. "We have to make it so it does each one of the functions," states Lou Burke, vice president of marketing and product strategy for 76 Lubricants Company in Costa Mesa, CA. "There's probably $20 million to $30 million of testing in all of the basic chemistry behind it, and then $1 million to license a diesel engine oil through the testing to prove that it meets the warranty requirements."

How the lubricant and fluid are used is defined by the application. "The ability to handle soot, as well as other contaminants, has become much more important," comments Burke. "[The grading industry] tends to be a dusty, dirty environment so your oil has to have a very good detergent package. When you're moving dirt, you are almost always operating on a fairly high load, which implies that you generate a lot of heat in your engine, and you don't want to have deposits form, particularly in your ring belt or around your combustion chamber."

Many oil companies will add a detergent to the lubricant to keep deposits from forming. "The detergent does a couple of things," explains Burke. "It stops deposits from forming. It can clean up some deposits, but that's not its primary function. It also acts as a base to neutralize acids formed in combustion. Acids primarily affect yellow metals mainly in rod bearings where you have coppers, leads, and tins."

Two other principal additives found in most lubricants are disbursants and antiwear constituents. Disbursants keep the combustion particulate from coagulating into larger masses that can clog filters and create plugs, which can limit the oil's effectiveness by constricting its pathways through the engine. Antiwear additives target the drive train, helping to reduce metal-to-metal wear in the valve train. Other additives include those designed to make an oil multigrade and antifoamants.

Making a Slick Decision

With all the different types of lubricants and fluids available, it becomes a challenge to understand what your needs are and what products will meet those needs. "It's generally difficult to find one lubricant that will serve all applications," observes Al Roush, vice president of research for D-A Lubricant Company of Indianapolis, IN. "Most applications have different requirements and different needs. You really must focus specifically on what each equipment manufacturer is intending his machine to do and how he's got that machine designed compartment by compartment."

Engines need a lubricant composition that will prevent wear and deposits and improve operational performance. In a differential or gear case that doesn't involve combustion gases but has heavy metal-to-metal contact, the chemicals in a lubricant prevent the metal surfaces from wearing under high unit loads. "They are totally different than the chemicals that you would put into a diesel engine," says Roush. "In fact, the chemicals that go into the gear train would actually destroy a diesel engine. They should never be mixed with one another. If you mix the engine oil with the extreme-pressure gear oils, you'll get all kinds of reactions in the gear case that would cause things like foaming and inappropriate wear protection."

Original equipment manufacturers (OEMs) establish the requirements for each piece of equipment they manufacture, so the most important starting point is their equipment specifications for lubricants and fluids. "The manufacturers are the key players," says Anderson. "They're saying these are the minimum performance and physical property criteria that the fluids should meet. As a reputable lubricant manufacturer, we have a responsibility to make sure what we offer meets that performance level before we recommend it for an application."

Engine manufacturers use minimum performance levels that have been developed by the American Petroleum Institute (API). These include a variety of evaluation procedures, such as physical and performance reviews that involve wear, deposit formation, cleanliness, foaming characteristics, seal compatibility, and so on. For hydraulic and drive-train fluids, most of the review is done according to manufacturer specifications.

Buying With Confidence

Fortunately for all but the smallest contractor (the one with one or two pieces of standard machinery), you don't need a chemical engineering degree to determine which fluids and lubricants you should use in your equipment. Often the expertise necessary to determine your total lubrication needs is as close as a phone call to your distributor.

But how do you select the right oil distributor? "A good one should be technically trained," states Burke. "They should tell you what the strengths are of the brands they're representing and how they can be used. They can also act as a conduit to contact the people behind the brand, the formulation scientists." Having confidence in the distributor is critical, emphasizes Anderson. "You want to be totally comfortable with the type of products that are being provided. You want to have some type of assurance that the products and recommendations offered are acceptable for your application and will provide the benefits that the supplier is indicating. Look at the supplier and make sure he can take care of all your lubricating needs-basically one-stop shopping. Make sure that your lubricant supplier can provide products in a timely fashion that's acceptable to the customer's operation."

In order to determine your lubricant and fluid needs, a top-line oil distributor will develop a comprehensive lubricant and fluid management program. This process often starts with identifying all of the various lubricant and fluid requirements for each piece of equipment and then determining those that overlap. All manufacturers have developed the necessary specifications. "The OEMs typically set the standards for the fluids that should go in their equipment," states Greg Raley, commercial product manager for Equilon Enterprises (Houston, TX), a joint venture between Shell Oil Company and Texaco Inc. "In the engine they usually specify API-licensed oils. In the power- and drive-train area, the OEMs are very specific about the types of products they want used. If people read their owner's manual, that will tell them what to use in what component."

Companies such as Caterpillar have specifications for coolants as well, says Raley. "The CAT EC-1 specification is for diesel engines. Traditional coolants require continual monitoring of the coolant system; specifically the level of coolant additives that keeps the liners from pitting and protects the system from corrosion. In traditional systems, you had to put some supplemental coolant additives (SCAs) in the antifreeze every 250 hours, and at 2,500 hours, you drain the antifreeze, recharge it, and start all over." New CAT EC-1 extended-life coolants reduce the maintenance frequency, thus saving costs and minimizing waste. "With these new extended-life coolants, you typically go 3,000 hours before you put in one application of extender, then go another 3,000 hours."

One high-value service that a good oil distributor should be able to offer is oil analysis (see sidebar). Oil analysis involves taking periodic samples of the lubricants and sending them to labs that analyze them for a variety of constituents. Oil analysis can identify potential maintenance problems before they become costly. "Oil analysis is an important maintenance tool in any operation," says Anderson. "It gives you excellent insight, allowing you to ensure that your maintenance schedules are proper and that you're getting advance information on the condition of the equipment. There's nothing worse than going out on a job, getting a third of the way through it, and then having some kind of problem that results in delays."

Dirt Can Hurt

"One of the biggest killers of construction equipment is dirt," states Scott Christie, marketing manager for DA Lubricant Company in Indianapolis, IN. "When you've got a container sitting around with a film of oil, it's like a dirt magnet. When you fill up that container with product, all the dirt goes in, and it doesn't take much to wipe out a piece of equipment. The good old common fill can is probably the worst thing because it's sitting out in that open shop. Somebody puts antifreeze in it one time, then engine oil, gear oil, or hydraulic oil the next time." The desire not to waste product could inadvertently cost more than the value of discarding contaminated product. "Contaminants have a negative impact on the way equipment operates," observes Bob Guillion, technical engineering manager for DA "Chemicals from one application might not fit at all well with other applications." Christie believes that there are times the chemicals should be thrown away.

Contaminants can come from any number of places. "The most likely place is through the air intake," says Todd Gardner, marketing manager with Castrol based in Baltimore, MD. "Dirty and clogged air filters or leaks in the intake system can ingest dirt and cause considerable damage. Leaking seals and water contamination in hydraulic systems can pull contaminants into the system and damage valves and wear pumps. In engine oils, the normal combustion process intentionally puts byproducts of incomplete combustion into the crankcase, causing wear and stress on the fluid and components. Proper maintenance procedures that include regularly scheduled oil drains, oil analysis, proper filter maintenance, and coolant system preventive maintenance will add considerable life to any component."

Water is another contaminant that can be destructive to lubricants. "It actually destroys the lubricant film that is necessary for separating metal parts," says Guillion. "There are chemical reactions that occur. Water has the effect of eliminating lubrication properties, which means you have excessive metal-to-metal contact." A lot of times, the contractor will store bulk fluids and lubricants outside where they are subjected to temperature fluctuations and weather. "You want to make sure that if you've got outside storage, you've got drum covers to help prevent water from getting onto a drum and seeping past the seals," suggests Ed Fliss, industrial and grease product manager for Equilon.

Improper grease application can also be an equipment killer. While the typical approach is to insert grease through a fitting while the machine is at rest, it doesn't necessarily ensure that grease has been adequately distributed through the component. "Let's take greasing an excavator," describes Guillion. "So many times when they're parked, people will just walk up and start greasing the attachments, the bucket, the stick, and the boom. What you need to do is exercise that attachment while you're greasing it to lubricate all sides of the pin. All those pivot points are pins and bushings. If you grease it in one position, you'll only grease half the pin."

Slipping Into the Future

The combination of increasing environmental regulation and demands for higher productivity will be the principal force facing contractors as they evaluate their lubricant and fluid needs. In addition, the oil industry itself is moving toward consolidation in order to improve market share and the bottom line. New products designed to meet these changing needs will appear, while old labels and brands will disappear.

"Probably the biggest issue diesel-powered equipment is facing is environmental regulations related to engine-exhaust emissions," states Guillion. "Most of the design changes in engines that occur from the impact of the exhaust regulations result in operational conditions that increase the amount of soot rejected to the oil, which potentially shortens the drain interval."

Equipment manufacturers are also working to fine-tune the performance of their equipment, which will increase the demands on fluid and lubricant performance. "We're seeing much more sophisticated equipment coming out on the market," observes Anderson. "This equipment is placing a higher level of stress on lubricants. It is running at higher speeds and temperatures, and the loading is higher. All of that is working the daylights out of lubricants." This is forcing manufacturers to constantly upgrade their products. "We're having to look at large reformulations every two to four years," comments Burke. "Engine technology is being driven by the Clean Air Act, and that changes the stresses on the oil." Burke cautions against resisting changes in the products that a contractor might use. "They're hurting themselves badly because the new technology product matches the new componentry and gets you maximum fluid and equipment life. We see some large construction fleets that are dragging their feet in making the move, and they're costing themselves money."

The bottom line is that fluids and lubricants are literally the lifeblood of the equipment. Contractors that recognize and manage this important aspect of their equipment will ultimately improve their bottom line. "Equipment operators owe it to their equipment to sit down and consider the different options out there," remarks Anderson. "I think they will find that if they consider the options and make changes accordingly, it gives them a slight competitive edge. Competition is exceptionally keen out there today. Why not try to lower costs any way you can?"