Grease Is The Word
Educate yourself about fifth wheel and chassis lubrication, and you just might find yourself singing a different tune about grease
Deborah Lockridge
Senior Editor
Extended oil-drain intervals. Longer trade cycles. Corrosive anti-icing chemicals. The environment — and environmental regulations.
What do these all have in common? They're reasons you should take a closer look at your chassis and fifth wheel lubrication practices.
You might think a grease is just a grease. But there's as much chemistry built into the formula of greases as there is in engine oils and gear oils, says Brian Jacoby, district manager of field engineering at Castrol.
"Because grease typically is not very expensive, people have a hard time believing there's that much technology involved," he says.
So, first, a grease primer.
The ingredient of grease that actually does the lubricating is oil, whether it's mineral or synthetic. To create grease, a "soap" is added to the oil. This soap acts like a sponge to keep the oil in place. The most common soap used for chassis grease is a lithium complex. Better-quality soaps typically mean the grease can withstand higher temperatures.
Additives in grease prevent rust and corrosion, keep it from washing off and allow better performance at extreme temperatures. Tackifiers make grease stick better. Thickeners are used to create more solid greases that stay where you want them. Solids, such as molybdenum disulfide ("moly") or asphalt, may be used for extra metal-to-metal wear protection under extreme conditions.
The National Lubricating Grease Institute (NLGI) provides standard ratings and certification for grease. Different thicknesses are designated with NLGI ratings from 6 (block grease) to 000, which is very fluid. NLGI No. 2 is typically used in chassis applications.
NLGI GC-LB is the highest performance category for multipurpose greases. GC refers to the highest wheel bearing performance classification, while LB refers to the highest chassis classification. By definition, GC-LB certification only includes NLGI No. 2 and No. 1 consistencies.
Chassis Grease: Which One?
You need to choose a chassis grease based on your specific needs, including such factors as oil drain intervals and whether you want a separate grease for the fifth wheel top plate.
"A trend I've been seeing for a long time," says Dan Arcy, Shell product manager for heavy duty lubricants, "is a lot of people use the same grease for everything — kingpins, fifth wheels, universal joints. There are different parts of the truck that can benefit from using specific products, like the fifth wheel, but a lot of fleets don't want to carry two products."
Adrian D'Souza, global grease technology team leader at ChevronTexaco, says having a "bumper-to-bumper" grease for all applications reduces the complexity of the supply chain. People don't have to keep track of which components need what grease, whether it's purchasing, inventory or on the shop floor. However, fleets might want to have different hardness grades of the same grease available for winter versus summer operation or for automatic lubrication systems.
Tom Boersig, ChevronTexaco Grease Technology research engineer, notes that while there are specialty greases available for fifth wheels, the company doesn't have a specific recommendation for a fifth wheel grease.
"All of the greases we recommend for multipurpose use on heavy duty trucks will be great for fifth wheels — as long as they are actually applied as recommended," Boersig says. "While good GC-LB multipurpose greases will do a fine job of lubricating fifth wheels, the reverse is not necessarily true. Why stock multiple products and have the possibility of misapplication?"
With many fleets extending oil drain intervals, chassis greases must work harder to keep up. Regular greases may require re-greasing at 12,000 miles. If you don't want to have to bring the truck in before that 25,000- or 30,000-mile extended drain interval, you need to use a grease that will last longer.
Dave Taber, technical coordinator for ConocoPhillips, says there are greases available that can handle these extended service intervals. "We've had to bolster the viscosity somewhat, look at partial synthetics. But those products do exist."
Even with a longer-lasting grease, you might want to consider shorter greasing intervals during the winter, when road salts and other de-icers — especially newer, more corrosive magnesium chloride — are particularly hard on grease.
"Fleets need to weigh the cost benefits and weaknesses of extended drain intervals," says Shell's Arcy, "and make sure they aren't giving up some of their preventive maintenance along the way."
Grease Techniques & Tips
With the trend toward longer service intervals, it's even more important that greasing is done correctly and completely.
"Even if we could make a grease that lasts forever, if it's not applied properly, it won't last a week," says Castrol's Jacoby. "I've never seen a grease out there yet that can overcome misapplication."
One of the most common mistakes is not purging the old grease. The very nature of grease means that unlike oil, it doesn't drain. The old grease must be pushed out, or purged, by fresh grease. Many mechanics don't use enough grease to purge worn-out grease and contaminants.
Warren Eckert, application engineer for ExxonMobil, says universal joints commonly fail because one of the trunnion joints is bone dry, thanks to inadequate grease.
"Quite often, mechanics will go through the numerous grease fittings and not take the time to really take a look and visually see that grease purging through," Eckert says.
Another factor in making sure the chassis gets lubed properly, says Eckert, is the grease equipment itself. It needs to be calibrated properly so it can push the grease through the tight-clearance components of the chassis. These settings must take into account the specific grease being used, he says. Extended service greases, he notes, often have different thickener systems that can make them harder to pump.
"Often what I find is a simple thing such as the air pressure through the grease pump is set too low," he says.
ConocoPhillips' Taber says it's also important to keep the seals and lubrication points in good condition. "If you get contaminants in those points, the grease can't do much about it. The grease is only as good as the seals that keep it in place and keep it clean."
Grease is relatively inexpensive, but you can still save on grease and disposal costs by minimizing waste. ChevronTexaco, for instance, puts grease liners in its containers, allowing the last of the grease to be squeezed out like toothpaste from a tube.
"I call it getting the squeal out of the pig," says ChevronTexaco's D'Souza.
Automatic Chassis Lubrication
Fleets determined to minimize shop time may benefit from automatic chassis lubrication systems. Trucks that see a lot of tough stop-and-go city traffic (probably the toughest grease test of all), or long-haul fleets that go high miles between shop visits are good candidates.
These systems are available from manufacturers such as Lubriquip, Interlube, Lincoln, Groeneveld and Vogel. While they all work a little differently, the concept is the same. Lubricant is pumped from a reservoir through tubing to the various lube points on the truck. A small amount of lube is released at specified intervals, perhaps every few hours of operation for an over-the-road truck, to keep the chassis constantly lubricated.
Because the grease used for chassis lubrication is usually too thick to pump through these lines — especially in cold temperatures — these systems use a semi-fluid grease such as an NLGI consistency 0 or 00.
Gary Picard, fleet sales engineer for Lubriquip, which makes the Grease Jockey system, says because the components are always lubricated, they will last longer.
Picard estimates that 11% of trucks in North America have on-board lubrication systems. There aren't more, he says, because most truck buyers balk at the upfront costs. "They say, 'What do I need that for? I've got Harry with a grease gun.'"
Lubriquip says the typical return on investment is two and three-quarters years. "Until about two years ago, when fleets were turning trucks over every three years, there was no real return on investment," Picard says. Now that some fleets are keeping trucks longer, there is increased interest in automatic chassis lubrication systems.
"When the automatic systems are working properly, they provide excellent protection," says ChevronTexaco's Boersig. "The caveat is that if they are relied on too much, without a diligent and knowledgeable human checking them occasionally, they can lead to catastrophic failures. They can plug up at times, have a small-size tubing break or leak, or just quit working for other reasons."
There's also some environmental concern about exactly what happens to the used grease each time the automatic system does its thing on the road. New California recommendations call for some type of used lube-recovery system on automatic lube systems when used for fifth wheel lubrication.
Fifth Wheels
Without lubrication, the fifth wheel and trailer bolster plate will essentially weld to each other — it's called friction welding — and drivers can experience lack of control and even jackknifing.
To prevent this, mechanics and drivers slather a copious amount of grease on the fifth wheel plate. But when the tractor and trailer are coupled, most of that grease gets squeezed out and ends up on the frame, trailer and ground.
Grease should be spread out in a thin, even coating over the entire surface of the fifth wheel plate.
"I see a lot of guys put a pattern on the top plate with the air-powered grease gun," says Roger Maye, national service manager for Consolidated Metco, which makes Simplex fifth wheels. "You don't need to have it standing up 3/8 of an inch thick. The trailer nose wipes most of it off the first time they couple."
Many fleets don't even use a grease gun. Instead, they use the residue from the bottom of grease containers and put them in a keg or bucket for fifth wheel use. Castrol's Jacoby says he has seen all sorts of application devices — brush brooms, broken boat oars, even sticks off trees — to slather on a pound or two of grease.
In addition to the fact that it wastes grease, over-greasing means a messy shop and more truck and trailer washes. A buildup of grease can obscure problems on the frame such as cracks or missing bolts. Too much accumulated grease in the locking mechanism of the fifth wheel can cause coupling and uncoupling problems. And grease on the truck frame can create a dangerous, slippery situation for drivers, leading to falls.
If those reasons don't get your attention, this one might. In California, environmental officials are targeting over-greased fifth wheels.
"If you take the number of trucks in the United States and multiply that by the amount of grease that's used on fifth wheels, about 100 million pounds of grease wash off each year," claims Art Cuse, who has invented a special fifth wheel grease <->— called Bullshot — that does not wash off. "Last week's lubing is this week's stormwater pollution."
In a new update of its Best Management Practices handbooks, the California Stormwater Quality Task Force specifically addresses the issue of fifth wheel grease.
According to Cuse, these handbooks are often used by local officials in regulating storm water pollution. For instance, he says, a city or county may require a trucking company to commit to a series of these BMPs, as they're called, before it will approve building or moving into a new facility. Other western states, where water supplies are scarce and storm water pollution is a concern, are likely to follow suit.
In section SC-22 on Vehicle and Equipment Repair, the industrial/commercial BMP handbook recommends the following options: Adhesive lubricant, plastic plates, fifth wheels with plastic inserts, and automatic chassis lubrication systems.
Adhesive lubricant
The fifth wheel is a unique grease challenge because it is so exposed to the elements. Fifth wheel lube is susceptible to what is called "water washout," where the grease is literally washed away by road spray. In the winter, the grease is exposed not only to road salt, but to the newer, more corrosive anti-icing chemicals being used by some states. And dirt and other solid contaminants that get caught in the grease can act like sandpaper.
Cuse's Bullshot fifth wheel lube was developed with these challenges — and stormwater pollution — in mind. The grease is designed to stay put on the fifth wheel — thus the term adhesive lube. It comes in a tube and can be applied with one hand. It's made of more than 90% food grade materials, so what little amount may wash off is not toxic. According to Cuse, it lasts two to 20 times longer than regular chassis grease. Only three ounces are needed to lube a dry fifth wheel plate, and an ounce for regular maintenance, he says.
There are a few other specialty greases for fifth wheels that offer some of the same advantages. Typically these use varying amounts of solid additives, such as moly and graphite. Even if the grease separates and the oil is no longer present to lubricate the fifth wheel, these solids are left behind to provide protection.
Castrol's new fifth wheel grease uses about 10% lubricating solids — moly, graphite and some proprietary solids — and a high percent of tackifiers to give it 10 times better adhesive properties than greases typically used for fifth wheels. In testing, it achieves a less than 1% water wash-off rating. A typical chassis grease, Jacoby says, might have 15 to 30% water wash-off. Because a smaller amount — 4-8 ounces — is needed, and because it doesn't have to be applied as frequently, the product is more cost effective as well as more environmentally friendly, he says.
Another option is Slik Pak, invented by a truck driver and distributed by Permatex. The custom-blended lubricant uses 30 percent graphite and moly solids. Rather than a tube, Slik Pak comes in sealed pouches that are simply placed on each side of the fifth wheel plate. When the tractor and trailer are coupled, the packets break and the lube is distributed where needed by the coupling action itself. This is a particularly easy way for drivers to re-lube fifth wheels on the road.
"You take four packets, stick them in your glove compartment and you can easily apply them at any time," says Mitch Bolinsky, lubricants product manager for Permatex. "Even in the rain or snow." Not only is it convenient, he says, it's also cost-effective. "It doesn't appear that way until you realize it's exactly the right amount of grease, exactly where you need it, each time."
Plastics
High-tech plastics and polymers are taking the place of grease in add-on plates and no-lube fifth wheels.
Plastic plates, such as the PlateMate, are composite plastic sheets that are placed between the fifth wheel top plate and trailer bolster plate to eliminate the need to grease the surface.
In many cases, however, the trailer kingpin must be sized to accommodate the lube plate thickness. If you use a lube plate with a standard kingpin, it may make the kingpin too short, resulting in coupling problems.
Some fifth wheel manufacturers warn that add-on lube plates should not be attached to the fifth wheel itself. This will change the kingpin interface dimensions of the fifth wheel locks, which could result in coupling difficulties, premature lock wear, and the potential to drop a trailer while the truck is going down the highway. In addition, some methods of attaching a lube plate to a fifth wheel could lead to fifth wheel cracking. Holland will revoke warranty coverage for any of its fifth wheels equipped with a lube plate.
Eugene Brown, manager of technical services at Fontaine Fifth Wheel, says he has seen customers who install these plates and then think the fifth wheel needs no lubrication at all.
"It doesn't relieve you of the responsibility of lubricating the other components, such as the moving mechanisms," he says. The result is steering problems, premature wear on the kingpin of fifth wheel locking components, or problems getting the fifth wheel lock to open or close.
The same type of technology is being used for inserts built into the fifth wheel plate itself. Low-lube or no-lube fifth wheels will soon be available from all fifth wheel manufacturers.
Low-lube fifth wheels feature top plate inserts with a low-friction compound such as polyethylene, which doesn't have to be greased. While these fifth wheels cost more than the traditional greased kind, they eliminate the mess that grease causes on truck frames and roadways, reduce environmental contamination and cut maintenance expenses.
So far, Holland Hitch appears to be the only fifth wheel manufacturer marketing such a product in this country. Since 1999, they have been selling their Low-Lube fifth wheel, which eliminated the need for greasing the fifth wheel plate and the bracket pockets/articulation plates. Holland's new No-Lube fifth wheel uses a new, stronger ultra high molecular weight insert compound. And it requires no lubrication on the fifth wheel lock or the components inside the fifth wheel. A laser coating process actually micro-welds lubricating alloys to the lock jaws, while the other components that previously required greasing, such as the yoke, yoke shaft, cam plate and lock points, are coated with a dry film compound.
However, low- and no-lube fifth wheels are not for everyone.
"Anything that requires the use of a fifth wheel is a pretty violent environment," says Fontaine's Brown. "Someone can drag a kingpin across the face of it, and the kingpin is made of steel and the fifth wheel plate is plastic — which one's going to give?"
These fifth wheels are not recommended for severe duty applications, or places where a lot of abrasives are present, such as construction sites. Trailers need to be kept in good condition, with no sharp edges and relatively clean undersides.
Greg Thorwall, who leads the fifth wheel engineering group at Holland Hitch, notes that even with the most durable material Holland engineers could find, drivers must be trained to use these fifth wheels properly.
"A greased fifth wheel is very forgiving of various coupling heights," he explains. "If a driver has a really low trailer, you just back up faster and hit it harder. We found that didn't work so well with low-lube fifth wheels."
The Holland lube plates are warrantied for two years, and with proper care will last longer, says the company. If they do get damaged, a replacement set runs around $100.
Fifth Wheel Tips
Instead of over-greasing fifth wheels, truck owners should pay more attention to how often the fifth wheel needs to be greased. Unfortunately, there's no hard-and-fast rule about fifth wheel plate lube frequency. Some drivers lube every time they change trailers. For many fleets the fifth wheel is serviced once a month.
Units operating with higher gross weights or in abrasive environments will need greasing more often, as will trucks that hook and unhook often, such as yard jockeys, or those running in winter weather conditions.
"A good visual inspection can quickly verify if your top plate lubrication procedures are adequate," says ConMet's Maye. If there are obvious signs of wear and areas with little or no grease, he says, the lubrication cycle is probably too long. Be aware of driver complaints about the trailer "pushing" the tractor.
The old grease should be scraped off the fifth wheel plate periodically and fresh grease applied. Old grease not only breaks down, it also attracts dirt and debris that can counteract the lubricating properties of the grease.
Don't forget that the fifth wheel plate is not the only part of the fifth wheel that needs lubrication. Even with a low-lube fifth wheel or add-on lube plate, it's important to remember to keep the lock and jaw lubricated, or you'll wind up with premature wear of the kingpin and locking jaw mechanism.
Even though grease might seem like a lowly part of your maintenance efforts, proper lubrication is nothing to monkey around with.
