Perfect Match

Aug. 1, 2005
Finding the appropriate truck to match the trailer is imperative to the life of the truck

There are a lot of considerations when it comes to spec'ing the right towing equipment for new trucks. According to Steve Broge, product application sales manager for Monroe, WI-based, Monroe Truck Equipment, finding the right type of truck and towing components means buying the truck that is needed, not just wanted.

"You have to make sure the GVWR is what it needs to be to pull the trailer or excessive weight, because a lot of damage will be done just by purchasing the wrong truck," he says. "The damage will not be limited to the trailer either."

PURCHASING CONSIDERATIONS
Broge says that when purchasing a truck, maintenance managers need to first consider the trailer they will need. "Finding the appropriate truck to match the trailer is imperative to the life of the truck. Also take into consideration the hitch and ball accessories to purchase as well. Just because a ball is spec'ed at 30,000 GVW doesn't mean your truck is."

Broge says most fleets work closely with trailer manufacturers for trailers that match their individual needs. Broge becomes uneasy when fleets purchase new trucks without matching the trucks to their trailers.

"You see these guys trading in one body type for a new one, and they don't notice the new truck is higher than the old truck. Now, the truck has changed, but the trailer hasn't."

Steve Harthorn's concern is that people don't know what companies have to offer as far as products.

"Not being aware of the capacities or articulation levels can get fleets into trouble," says Harthorm, product manager for coupling products and kingpin group, The Holland Group Inc.—Holland USA. He says the ability of the suspension to move under the load directly affects how that load will be carried.

MORE THAN COMPONENTS
"If a fleet is doing a lot of towing, using a better grade of engine oil will be important. Using a synthetic transmission oil will also help with the excessive heat when towing," Broge says. "Clutch grease will plug up the filter, which will increase the running temperature. All of these factors determine how your transmission will run."

Adjusting the intervals at which lubricants are changed is just as important as the quality. Changing the oil more often on towing vehicles will provide better protection for the components. Sample schedules and suggestions can be found in manufacturer literature.

Brake controllers are also something to be considered in purchasing. Maintenance managers should work directly with the trailer manufacturers to spec' the appropriate brake controllers for the trailer.

"When the appropriate brake controller is spec'ed, stop-ability is better, you will have more control and there will be less maintenance to the truck," Broge says.

Harthorn says manufacturer's websites are great sources for help on component selection and maintenance suggestions. "Here at Holland, we offer everything from before you buy to how to fix it. It's a great resource."

LARGER HAULS
Once a maintenance manager decides on a trailer, depending upon the weights of the loads, a hitch and ball may not be enough, says Harthorn.

"Here's a guy in the bulldozing service and he has a truck but tows a dozer from jobsite to jobsite, and he may require a 20,000 pound capacity, but when you get into that much weight, the conventional ball hitch doesn't work anymore. That's when you go to the pintle hook and the drawbar because of how the weight is distributed," he says.

Pintle hooks, couplers and mating drawbars are for commercial and industrial towing applications where capacities usually exceed 10,000 pounds gross trailer weight. These components are designed to be used primarily for towing and where backing up of vehicles is limited.

There are two types of ball hitches. A weight-carrying hitch consists of a ball and coupler with no means to distribute the hitch weight. It is used primarily for lightweight trailers. Heavier trailers, however, require a weight-distributing hitch, which uses spring bars to transfer some of the hitch weight forward onto the tow vehicle's front axle and rearward onto the trailer's axle(s).

VARYING THE LOAD
Harthorn warns maintenance managers to keep in mind what kinds of environments they will put their trucks and trailers through when considering load sizes.

"If the trailer goes off road, OEMs require fleets to reduce their loads by 25 percent with pintle hook equipment," he says.

"Also when you go off road, you have a situation with articulation. The problem is rigidity. If they don't have either a swivel pintle hook or a swivel draw bar to restrict movement, the problem will be things breaking because it is able to bang around," he says.

Loading the trailer should also be taken into consideration.

"For example, how the load is distrib uted with the basic weight ahead of the trailer axles, you will end up with a huge vertical load on the coupling joint," Harthron says. This will be a problem because you can exceed the vertical capacity of the coupling joints, which can lead to a failure.

"Matching the components up, making sure the loads are equal—the tow vehicle and the towed vehicle—and also keeping an eye on how the trailer is being loaded—these are the best ways to prevent component failures," Harthorn says.

A NOSE UP
"Have you ever seen a truck pulling a load, and its front end is up in the air?" asks Monroe's Broge. "This occurs when the truck is pulling a trailer that is too heavy."

Broge mentions that there are trailers out there where people can flip the springs to raise the trailer up a few inches, but he says that scares him.

"Call me old school, but when it comes to safety, the higher the center of gravity, the more likely the truck could tip. Just because the truck may have enough power to pull the trailer, that doesn't mean it is appropriate."

Broge says a good way to lose a warranty is to tow a trailer that is too heavy. Many times, He has dealt with customers demanding warranty service on their brakes after only 17,000 miles.

"Part of warranty servicing is trying understand the problem. All we have to do is take one look at the trailers that are too big and too heavy for the trucks to find the real cause," he says.

Maintaining a warranty should be enough to motivate people to maintain their vehicles, but Broge says that's where people miss the target.

MAINTAIN LIFE
According to Harthorn, some pintle hooks require grease or light oil in the pivot points to keep them moving.

"Another situation we have is, because of the fact that these are on the back of the truck and the driver can't see what he's doing, the latches of the pintle hooks get damaged. You need to constantly check the components to make sure that the operation of the pintle hook and the latch assemblies are in good working order and haven't been damaged," he says.

"A final concern is wear. The drawbar eye and the horn of the pintle hook will wear."

Harthorn suggests that maintenance managers consult component catalogs for specific dimensions for component wear.

"Inspect the coupling contact area and periodically disassemble to inspect for wear, shank and latches, etc. Replace any component when wear exceeds an 1/8 of an inch (0.125) from the original surface profile," says Harthorn.

Harthorn recommends to check equipment more often if you are going off-road.

"There isn't really a lot you can do to prevent wear. You don't want to overload it, or exceed capacities which could not only damage the pintle hook and the trailer, but also your truck. Be sure to check the torque of the bolts that hold the components on the vehicles as well," he says.

"Just keep it well lubricated and check for wear. If the wear goes beyond what is considered safe, replace it," Harthorn suggests.

LONG LIFE
Broge says the key to a happy owner is education.

"It is my belief that the cus tomer should sit down with their dealer to discuss their needs before purchasing," he said Harthorn wants maintenance managers to reflect on the positive aspects of towing component maintenance.

"If maintained and inspected properly, towing components will usually last longer than the trailer, and with any luck," he says, "you won't ever have to replace the components throughout the life of the truck."

Sponsored Recommendations

Are you aware of the hidden costs lurking behind ignored maintenance? This eBook reveals how neglecting upkeep can inate repair bills, induce downtime, and harm reliability. ...
Are your KPIs driving real fleet improvement? Learn how to set smarter, data-driven benchmarks, track success like top-performing fleets, and apply proven strategies to optimize...
Fullbay's fifth annual State of Heavy-Duty Repair compiles insights from almost 1,000 experts and over 3,500 shops. If you aren't leveraging these proven data points, your competition...
Quality body repairs on medium- and heavy-duty trucks depend on the use of specialized adhesives, sealers, and other allied materials. Unfortunately, many shops face challenges...