It's possible to consolidate greases used in your fleet, but you must understand the applications and tradeoffs. Speed, temperature, pressure and working environment influence selection. "Over 95% of the construction applications are slow-moving, articulating components that have high pressures and a tendency for contamination," says Mark Betner, Citgo.
Staying power - the ability to not leak out under high breakout forces - is one of the most critical requirements. "The first thing you should look for is a grease that will stay put so you don't have to constantly re-lubricate; or one that will at least last for a reasonable period of time, where you can [maintain] your regular maintenance schedule without causing high wear in the components," says Betner.
Grease must contend not only with the physical forces it encounters, says Betner, but also with water and the potential for dirt contamination. In some cases, the grease must also survive high temperatures.
There are "all-purpose" grease products that will work in these situations, but at a price. Improper selection or application of grease is one of the biggest causes of lubricant-related failures, according to Bob Theisen, manager of technical services, CHS Inc., manufacturer of Cenex brand products. "Lubricant-related failure of almost any type of grease falls into a handful of categories. It is either the wrong type of grease for the application; incompatible greases were mixed; or contamination was introduced, causing excessive wear and premature failure," he explains.
"If you are going to try to use one grease for everything, I can almost guarantee that something is going to get compromised to some degree," adds Betner.
When planning to consolidate greases, identify your most severe applications. "Where is the greatest likelihood of having repairs as a result of using a grease that is not up to the job?" asks Betner. "Do you want to select a grease that will protect the most severe application first and foremost, or do you really consider all-purpose more important?
"Everybody wants to simplify life and reduce inventory," he acknowledges. But with the cost of the equipment, downtime and repairs, it sometimes makes more sense to carry different products for the most severe applications.
Similarly, don't let occasional-use applications play too large a role in your main grease product selection. "If a tool salesman came in and told you to throw all of your different tools away, then offered to sell you the best Crescent wrench in America, what would you do?" Betner asks.
He admits that some greases do a very good job of balancing multiple demands. Your lubricant supplier is a good source for this information. "We can come up with one product that will do a fairly good job at almost everything, but it will not do the best job," Betner adds.
Base oil determines application
Grease consists of three main components: a base oil, a thickener and additives that enhance performance. While greases may all look the same, it is important to realize how complex these formulations really are.
Heavy-duty construction-type greases generally have higher oil viscosities. "Bucket pins, hinge pins, dump beds - anywhere you have a tremendous amount of weight pivoting back and forth can benefit from using grease with higher viscosity base oils in their makeup," says John Geyer, grease business manager for industrial and integrated solutions, Chevron. The heavier the load, the higher the viscosity of base oil you will often want to prevent as much metal-to-metal contact as possible.
Lighter oil viscosity multipurpose greases can often be squeezed out between surfaces. "You can actually wind up with metal to metal contact," says Geyer. But the lighter oil viscosities do allow these multipurpose greases to work in a broad spectrum of climates. "The issue is that they don't always afford you the best protection on the equipment."