When grease is good

Oct. 1, 2003
GREASE is the ninth-longest-running show in Broadway history, and spawned a successful movie. Grease, minus the quotation marks and Olivia Newton-John

GREASE” is the ninth-longest-running show in Broadway history, and spawned a successful movie.

Grease, minus the quotation marks and Olivia Newton-John and John Travolta, is something entirely different.

It helps to know exactly what it is, which grease is suited for various applications, and how to apply it.

Shell product marketing manager Dan Arcy says a base stock of oil — mineral or synthetic — is the ingredient in grease that performs the lubricating, joining with a soap (a lithium complex, most likely) that has sponge-like properties.

Grease also consists of: chemical additives that combat corrosion; and thickeners that are used to create more solidity so the grease remains where it is applied.

“The lubrication of the bearings, or whatever you're putting the grease in, is actually being done by the oil that's in there,” Arcy says. “The soap you're adding to thicken it actually works more or less like a sponge to hold that oil in place so that it can't leak out.”

According to Shell, grease should be used as a primary lubricant when:

  • The use of an oil is not practical.

  • The equipment is not designed to use oil or retain oil.

  • The mechanical sealing properties provided by the grease consistency/texture is beneficial.

  • It is less maintenance intensive.

  • Cooling of equipment is not a function of the lubricant.

Properties

There is a different portfolio of greases for mobile equipment, he says. Mobile grease has to be more multipurpose because the loads, speed, and operating conditions vary so greatly.

According to Arcy, important grease properties for mobile equipment are load-carrying capability, resistance to water washout, and corrosion protection.

Shell's product line of mobile equipment greases includes:

  • A core: Lithium complex for on- and off-highway use.

  • Three general: lithium plus 3% molybdenum disulfide, or moly, for general automotive and some industrial use, lithium complex plus 3% moly for heavy equipment and heavy automotive and industrial loads, and lithium/calcium for severe loads and high water contamination in automotive and industrial applications.

  • Specialty: lithium complex for truck trailer wheel ends.

He said the core grease has excellent high-temperature performance and water resistance, and its uses include heavy-duty truck service, wheel bearings, chassis, kingpins, universal joints, and fifthwheels.

“Some greases have polymers in them, or some type of agent that causes them to be tacky or sticky,” Arcy says. “You may want that in a bushing-type application, or a fifthwheel. For a wheel bearing or U joint, you definitely don't want a tacky grease because it won't fill back in the crevices, and you'll have issues with improper lubrication.

“If you're going into a high-speed bearing, you're going to want a grease with a lighter-type base oil in it versus a slow-speed application where you're going to want heavier-type base oil.”

He says that NLGI Grade 2 type greases generally are good for all components on a truck, except wheel ends.

There are a lot of different opinions about what is best for a fifthwheel, according to Arcy.

“From a cost perspective, some people don't want to pay that cost benefit for that higher-priced product,” he says. “They buy an economical grease and use it more often. Others buy a more premium product and grease less.

“I'm not going to tell you which is best. But I recommend in all fifthwheel applications that you go with something that has a moly-type lubricant.”

He says one of the biggest problems with fifthwheel greasing is that it is overdone.

“It's not like you're going to cause any damage,” he says, “but you waste grease and have the potential of pushing excess grease out into the environment.”

About the Author

Rick Weber | Associate Editor

Rick Weber has been an associate editor for Trailer/Body Builders since February 2000. A national award-winning sportswriter, he covered the Miami Dolphins for the Fort Myers News-Press following service with publications in California and Australia. He is a graduate of Penn State University.