Article

Maintenance Report: Trailers

Attention to detail in spec'ing and maintaining trailers pays off in longer life and lower maintenance costs.

November 2008, TruckingInfo.com - Feature

by Deborah Lockridge, Senior Managing Editor

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Trailers these days get a little more respect than they used to. They're designed to last longer with less maintenance. Newer, more damaging de-icers have driven the development of new coatings and other solutions to corrosion problems. Trailer tracking systems allow fleets to keep track of both tethered and untethered units.

Like tractors, trailers require maintenance on brakes, wheel-ends and tires, which we've addressed in depth in other articles. But there are a lot of little, simple things you can do to help your trailer last longer, with less time and money spent on maintenance in the long run.

Some of these things you may not have thought of. Others may be overlooked in the day-to-day hustle of the trucking business.

SMART SPEC'ING

The first step to a relatively trouble-free, long-lived trailer is the spec'ing process.

"If you spec good equipment out of the gate, over the long term your maintenance expenses are going to be a lot less," says Travis Hopkey, director of marketing for Phillips Industries, which supplies air and electrical products. "As we like to say, 'To pay for quality, you only have to flinch once.'"

It's important to spec the trailer properly for the application, keeping in mind the wear and tear it's likely to get during its life. There are also many options available that may cost you a little more up front, but will more than pay for themselves in less maintenance down the road.

"The biggest thing to do in keeping maintenance costs down is to be diligent in the way you spec the equipment," says Tim Gilbert, director of fleets and heavy-duty OEMs at Peterson Manufacturing, a lighting and electrical supplier. "My advice to fleets or owner-operators is never be afraid to contact a component manufacturer to make sure you're getting the whole story on what the capabilities and the application should be. You don't necessarily have to take what the OEM is giving you. Be diligent and do your research and make sure you get the biggest bang for the buck."

Often, trailer buyers spec brakes and tires and the more expensive components on trailers, Hopkey says, "but focusing on smaller elements can really make a difference in maintenance costs."

For instance, sealed and modular wiring harnesses are standard now on many trailers, and if not, you should be spec'ing them. These harnesses keep out corrosion-causing moisture and de-icing chemicals. And if part of the wiring is damaged, for instance by a blown rear tire, part of the harness can easily be unplugged and replaced, points out Page Large, national fleet sales manager for lighting and electrical supplier Grote Industries.

Another commonly recommended spec is LED lighting, which is increasingly standard on trailers. It may cost more up front, but lasts many times longer than traditional incandescent lighting. If you're planning to keep your trailer longer than three or four years, LED lighting is a smart spec. At the very least, Hopkey says, spec LEDs on the top rails. "Thieves typically won't climb up a ladder to steal them, and that's the one that's expensive to repair."

The backside of lights are exposed on flatbed trailers, making them susceptible to corrosion-causing moisture and chemicals. On incandescent lights, that was addressed via a close-backed grommet. But when LEDs came along, mounted in a flange rather than a grommet, the backside was again exposed, explains Grote's Large. "So we developed a snap-in piece a few years ago that serves the same purpose as a close-backed grommet. We developed a cup, if you will, that snaps into the backside of a flange, so you're protecting your LEDs with a protective cover."

You may be able to extend the life of your brakes and your trailer tires by spec'ing a quick-exhaust or quick-release gladhand, Hopkey says. "Typically, air has to escape all the way back up to the tractor," he explains. "But with a quick-release right in front of the trailer, the air can escape a lot quicker." Too often, he says, drivers are already taking off before the brakes on the trailer have released, creating a "hop" or "bounce" of the trailer and putting more wear and tear on those brakes and flat-spotting tires.

While you're spec'ing gladhands, an anodized or cast iron gladhand will last longer and be more resistant to corrosion than the less-expensive aluminum ones. In addition, a polyurethane gladhand seal will last longer than the rubber kind. And if you're going to drop trailers, use a screen or a gladhand seal with dust flaps to keep bugs and other contaminants out of the air system.

Keeping to the air system, air lines are the focus of some new corrosion-resistant developments at Sloan Transportation Products, according to Tony Prusinski, marketing and product manager. Sloan uses a salt- and moisture-resistant plating initially designed for naval ships to fight corrosion on its new MaxxDuty hose assembly. These assemblies retain their swiveling ability and ability to be disassembled even after long-term exposure to corrosive chemicals.

THE TRACTOR-TRAILER CONNECTION

Remember when the government started requiring antilock braking systems on trailers, and the industry was worried that the traditional seven-way connector wasn't up to the job? Manufacturers figured out how to do it, but now think about all the other electrical signals and information that also travel back and forth between the tractor and trailer - trailer tracking systems, stability and anti-rollover systems, tire pressure monitoring, axle-based weight info, and more. This means it's more important than ever to think about that connection when spec'ing and maintaining it.

Grote, for instance, recently developed a new nose box for the front of the trailer. "With the increasing complexity of systems that fleets are wanting installed on trailers, the real estate of the existing design of the seven-way connector at the front was just not too efficient in the assembly process," says Large. "We developed a brand new nose box that allows for these systems to be installed on new trailers easily and efficiently." It also makes maintenance easier, he says. If you find evidence of corrosion in a connector, you can just remove and replace it with a new connector instead of installing an entire new nose box.

The tractor-trailer electrical connection gets doused with road spray, so take steps to prevent corrosion. Routine maintenance for the connector includes pulling the plugs apart, checking the connections, regreasing and plugging them back in.

A very simple tip recommended by Phillips is to swap the ends of the cable at every PM. "It's so simple, but no one ever thinks of it," Hopkey says. "If they're dropping trailers, that end gets plugged and unplugged frequently and is kind of self-cleaning. On the tractor, they'll start corroding together."

Rod Ehrlich, senior vice president/chief technology officer for trailer maker Wabash National, cautions against a common industry practice of spec'ing "split" connector pins on the trailer side. The theory is that when the connectors start to wear out, the split will allow the pin to be widened using a screwdriver so it can at least make a temporary connection.

"We try to inform the buyer that it's better to use a solid pin on the trailer, and when the connection doesn't make a good connection, the part that needs to be repaired is the part on the tractor," Ehrlich says. "When they spread the split brass pins on the trailer, you can only do that once or twice, and then the pin breaks - and then you're totally out of luck. That's just a poor maintenance practice."

ELECTRICAL SYSTEMS

"A lot of people don't think of electrical systems needing maintenance, but grease does dry out on you," says Peterson's Gilbert. Not all, but many electrical connections require grease, especially the seven-pin connector between the tractor and the trailer. Read the manufacturer's recommendations to see which connectors require grease, and make sure you use dielectric grease designed for electrical systems (sometimes called dialectric.) "Normal grease would have way too much water in it and cause more problems than it solves," Gilbert says.

Too often, says Wabash's Ehrlich, when mechanics replace a light and discover it's corroded, they just knock off the corrosion, plug it back together and send the truck on its way. If you do this, "it will work when you put it back together, but chances are, the next time, the terminals will be disintegrated," he says.

Grote's Large cautions that there's such a thing as too much grease. "Sometimes guys want to fill the connection full of grease. That's actually a bad thing, because you could create a hydraulic effect, which pushes the connector off the lamp over a period of time, because there's no place for all that grease to go."

While modular harnesses may have made it easier to repair and replace, don't be tempted to take shortcuts, Large says. "We strongly recommend that you properly secure that harness back to the frame rail the way the OEM did it. We'll see shortcuts; they unplug the damaged portion of harness and plug in the replacement part, and they fail to use the proper number of wire ties to secure the harness back to the frame rail. If that harness is not properly secured to the frame rail, just the mere weight of it causes stress on the connections." In northern climates, if a harness is not properly secured and a lot of ice and slush accumulates on it, it can cause a short or can even cause the harness to come unplugged.

Another shortcut to avoid is using too light a wire when adding something like an indicator light for tire inflation systems, says Wabash's Ehrlich. "We use minimum 12 gauge wire on trailers, because if it shorts out, it's heavy enough not to start a fire before it trips the circuit breaker on the tractor. So always use a heavier gauge wire than is needed for the amperage requirements of the device." If you don't, he says, you may save 10 cents on the wire, but you can burn the entire trailer down.

Gilbert also points out a small thing that is sometimes overlooked during maintenance procedures: properly installing directional lights.

"A lot of manufacturers out there make lights that are directional, where there's a top orientation to them," he explains. "If those get rotated in any way, you're actually running a non-compliant lamp. If there's a top marking on there, they need to make sure it's on the top. Some of these lights are getting pretty small and you have to look really close for that top marking."

And if you have to go in and troubleshoot wiring problems, do it correctly. Don't pierce the wires, which creates a place where corrosion-causing chemicals and moisture can get in.

"A [wiring] jacket is sort of like a hollow tube of spaghetti," Ehrlich explains. "There is air in and around the bundle of wires in a cable. Once you put a pinprick into the cable jacket, it will suck water in as it cools down. There's actually a vacuum created inside that wire, and it will pull moisture in and feed it along the wire," causing corrosion. "I've seen it run feet away from a damaged surface - not a matter of just inches."

INSIDE JOB

Don't forget the inside of the trailer. Interior liners and scuffs can be spec'd to reduce damage during loading and unloading.

"Interior wall damage on both reefers and dry freights has always been a maintenance issue," says Craig Bennett, senior vice president of sales and marketing for Utility Trailer. "The trend recently has been to high-strength interior liners on reefer trailers, and the wear bands have been upgraded to be stronger. On a dry van trailer, the trend has been towards the high-strength steel liner."

These damage-resistant liners extend repair/replacement requirements significantly, says Ron Gordy, director of quality assurance for Great Dane, compared to the old plywood-lined sidewalls that would have to be replaced during the trailer's life.

If you have wood floors, a little preventive maintenance can prevent damage from rain that gets inside when trailer doors are left open.

"Wood and water don't mix well," says Wabash's Ehrlich. "Just like if you have a wooden deck at home, if you want it to last a long time, preventive maintenance is to periodically put a wood shield on it. There are a lot of materials out there that penetrate the surface of the wood and prevent water absorption. And you don't need to treat the entire floor; the problem is only at the rear portion of the trailer."

CORROSION CONTROL

Corrosion prevention is a hot topic in trailer circles these days, and one of the best things you can do to prevent it is keep the trailer clean, especially the structure underneath - especially during the winter months.

"Ultimately, the biggest prevention you can do to ensure a safe and long-lasting trailer is to make sure, after you make a run through bad weather conditions, that you have your trailer washed down," says Sloan's Prusinski.

Dan Giles, director of engineering for Fontaine Trailer, says he's seen trailers that were one or two years old that showed excessive signs of corrosion, a situation that could have been prevented with frequent washing.

"I think there are times when washing may be looked at as a luxury," says Charlie Wells, director of dump trailer products and dealer development at East Manufacturing. But in reality, it's an important part of preventive maintenance.

"I've seen fleets go through the whole winter quarter that the trailer was never washed," says Great Dane's Gordy.

Yet as important as washing is, it needs to be done right. "Many owner-operators and fleets are pressure-washing trailers, and if it's not done correctly, they're mitigating corrosion but damaging components and parts," Giles says.

Gordy recommends using low-pressure warm water wash and rinse. You could wash off protective coatings by using high pressures.

No matter how much you wash, you still may find some corrosion. The key is to catch it early and do something about it, says Wabash's Ehrlich.

"I sort of liken it to cancer," he says. "You need to remove the problem to stop it, because it grows once it starts." To keep corrosion from spreading, he says, remove the visible corrosion crust and treat with one of various sealants available on the market.

"The crusty material you see around corrosion holds salt water," Ehrlich explains. "Even when the trailer is dry, or even when it's been washed and cleaned, those pockets do not get drained of the salt water. Consequently, the salt water continues to work on the metal 24 hours a day."

INSPECTIONS

You have to inspect the whole trailer top to bottom at least once a year for the annual DOT-required inspection, but that's not enough.

"I think a good maintenance program is every time the trailer is in, that it gets looked over," says Utility's Bennett. "If there are cuts on the wall, they need to get repaired right away, particularly on a reefer - don't go out on a second or third trip and allow moisture to penetrate the foam of the sidewall," which will only result in a more expensive repair down the road.

East's Wells notes that his company's operating manual lists periodic inspections - six-month, monthly, weekly, and daily trip inspections. Wells, who is also a pilot, compares it to a pilot's pre-trip checklist. Proper inspections, he says, are "probably the single biggest thing from a maintenance standpoint. You may see some little telltale sign, like a little drop of oil, and you've got to ask yourself, 'What caused that?' Sometimes catching things at the earliest stages is the biggest savings one could find."

Fontaine's Giles believes most trailer owners could do a better job of periodically inspecting the underside of the trailer, especially flatbeds. Cracking is an issue with flatbeds, simply because of the nature of the application and the loads.

"Our recommended practice has people looking at the trailer at least once a month," Giles says. "If any damage has occurred, say from running over road debris, or the trailer starts to show any signs of fatigue, they would catch that early on. A lot of times, things can be repaired, and even repaired under warranty, if they're caught early on. If not caught early, it can become a major problem."

Don't neglect hidden areas that will require a mirror to check, says Great Dane's Gordy. "A lot of weldments in the trailer understructure are basically hidden from immediate view, like the upper slide rails of the suspension to the bottom flanges of the crossmembers. It's very important those be checked during regular PM schedules."

It may take a fiber optic camera, but another hidden area that's prone to corrosion is the interior of the kingpin section, says Chuck Cole, manager of technical sales and product training for Utility. Because of its position above the tractor's rear tires, he says, it's prone to getting filled up with sand, salt, and corrosive de-icing chemicals. And many corrosion coating processes, he says, may miss some of that area.

"We have heard that there is a problem in the industry with people having failures of the kingpin section due to corrosion," Cole says. "If you were to take a camera and go inside and look, you'd be surprised at what you see as far as the loss of material thickness" due to corrosive chemicals that are nearly impossible to wash out.

Gaskets and seals around doors, vents, and reefer units should be checked, not only during PM inspections but also during regular driver walk-arounds, Gordy says. The gaskets around rear doors, especially, are susceptible to damage during the loading and unloading process and should be repaired or replaced promptly if torn or dislodged.

"On refrigerated trailers in particular, air loss out of the box affects run times of units, and gaskets around the nose-mounted unit or around doors and vents need to be maintained to keep the box air tight," Gordy says. "And on dry freight trailers, it's equally important to keep water out - that's the reason they call them dry freight. If you don't maintain those gaskets, you can get water ingress."

KNOWLEDGE IS POWER

It may seem obvious, but check the owner's manual for recommended maintenance intervals and procedures.

Other sources of information include the Truck Trailer Manufacturers Association and the Technology and Maintenance Council of the American Trucking Associations. TTMA has a Trailer Maintenance Manual available for $195, which covers van, platform and dump trailers. In addition, specific Recommended Practices and Technical Bulletins are available for purchase, such as a technical bulletin on pressure washing. TMC's Recommended Maintenance Practices manual offers numerous RPs, as they are called, that deal specifically with trailers, including details such as maintaining the rear impact guard, the upper coupler assembly, and load securement/anchor points.

And don't forget the resources and training provided by the suppliers of components on the trailer. Manuals and training are available for everything from suspensions and axles to wheel-ends and the electrical system.

Most importantly, don't be short-sighted and try to improve today's bottom line by ignoring the little things that can add up to big bucks later on.

"A lot of fleets these days are not doing maintenance as much as they were in an effort to reduce costs - it's a pay me now, pay me later type of thing," Bennett says. "And if you pay me later, it's usually more."

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