Don’t Let Trouble Sneak Up from Behind

Is it Hank’s imagination, is he getting old, or is your top driver right when he says it’s really getting harder to crank the landing gear on his trailer?

Landing gear is one of those things that-like the trailer itself-is too often neglected. The same can be said for scuffs and other types of damage on the trailer’s floor and roof: out of sight, out of mind, right?

Here are some quick tips to help bring problems with your landing gear, floor, and roof to the forefront-and prevent trouble from sneaking up on you from behind.

LANDING GEAR

Like Hank’s bone joints, the gears inside the cranking mechanism may not be as limber as they should. And lube can get stiff, especially in cold weather. That’s to be expected.

But what about a gear that gets used a lot, as in hook-and-drop operations?

Cranking very slowly consumes grease, and it ought to be replaced. Most fleets check this on a quarterly, semiannual, or annual basis. Does the mechanic remember to re-lube the gears with the recommended grease? How about operation of the cranking mechanism, in both high and low speeds? It could be that something needs adjusting. If you’re the mechanic (or you talk to him), here’s your reminder.

More obvious is misaligned or bent legs, usually the result of someone backing under the trailer at an angle or mistakenly pulling away before the gear is cranked all the way up. This shouldn’t happen when backing under a trailer unless the nose is especially low and the trailer is rammed really hard. Today’s spring brakes apply when the trailer’s air supply is disconnected, keeping the vehicle in place as the tractor’s fifth wheel forces its way under the trailer’s nose.

(In the days before mandatory spring brakes, landing gear legs could also be bent if the guy backed under the trailer before hooking up the air hoses and charging up the brakes to apply them. With no brakes applied, the fifth wheel could push the trailer backward, its wheels rolling freely but legs dragging on the ground. Such trailers today would be 20 or more years old; do you have any of those?)

A well-spec’d trailer will have legs built stout enough to take a certain amount of abuse. But many trailers are built for low selling price, so money has to be taken out here and there. One place is the legs, which may be built of lower-yield steel or with fewer cross-bracings than normal. Ask your drivers to be on the lookout for these and to exercise care in backing under them. One good whack from an angle could push the legs sideways and bend them.

Even good legs can bend if repeatedly pushed at an angle. So drivers should follow some simple rules when hooking onto a trailer:

Approach the trailer from directly in front. If another vehicle is in the way of the trailer, find its owner or a yard tractor and get it moved.

If the trailer must be coupled from an angle, approach slowly, then stop just as the fifth wheel contacts the trailer’s nose. Get out and check the situation.

If the nose is lower than the fifth wheel such that the wheel’s ramp cannot slide under the nose, adjust the relative heights by bleeding air from the tractor’s airbags or cranking up the trailer (it’s hard work, but it can be done if the gear’s set on low speed to get the greater mechanical advantage).

Ease the fifth wheel under the nose and watch to see if it’s being pushed to the side. If so, stop and adjust the nose height some more, then try again. If the tractor had to be lowered or the trailer’s nose raised, adjust the legs upward after the fifth wheel plate begins sliding under the nose; otherwise, the jaws won’t grab enough of the trailer’s kingpin to latch on securely.

A vigorous pull-ahead test will make sure the jaws are firmly in place. Hook up all lines, release the brakes, pull ahead slowly, then gently apply the trailer brakes (if the tractor has a “trolley” handle) to double-check the hookup.

Drivers should remember that if they damage the landing gear, they might have trouble dropping the trailer later. Bent legs can cost hundreds of dollars to fix. The rule is golden: a little care now will save time, effort, and money in the future, guaranteed.

DON’T IGNORE THE FLOOR

Some fleets keep van trailers in service for 15 to 20 years, and their floors look it: planks are split, torn or missing altogether; occasionally you’ll even see gaping holes, revealing crossmembers, running gear, and the pavement below. Don’t cheap out and risk the limbs of a loader or driver, not to mention valuable cargo. Spec a high-quality floor and maintain it.

A well-built floor has quality materials that have been seasoned, cut, milled, and treated, then stoutly installed. Fix damaged strips or boards as soon as possible. A few well-placed screws can keep down ends; warped materials should be cut out and replaced with new wood that’s cut to fit.

But before screwing these down, slap on some moisture-resistant end coating. Coating controls and checks splitting and warping caused by rapid or uneven loss or gain of moisture. Usually the end coating is a wax emulsion; preferably it should be of the same type originally used in the floor, or at least something similar. Your trailer shop probably has some coating in stock; if not, check with a trailer dealer.

If the trailer is to be disposed of soon, healing wounded floors with replacement hardwood pieces, and coating them before installation, may not seem important. But doing the job right suggests that the vehicle has been well maintained elsewhere and will probably fetch a higher price.

ROOF TAKE A HIT?

You know your roof has to be fixed quickly or moisture will work its way inside, damaging cargo and the rest of the vehicle. The overall rule for repairs to the roof and the rest of the trailer body is to use what the manufacturer did when assembling it. Consult the OEM or your dealer for tips on techniques and materials.

Whether you get advice or wing it, do the repairs correctly. The roof is part of a van trailer’s monocoque structure, and the body loses much of its rigidity if the roof hasn’t the strength that was designed in.

In reattaching roof sheeting to the bows, use squeezed or bucked solid rivets, which are much stronger than hollow “blind” rivets; or Grade 5 cap screws, which are likewise strong, especially if torqued to the correct specifications.

Torque specs for Grade 5 threaded fasteners likely to be used in roofs vary from just a few foot-pounds to more than a hundred. The inch-pound or foot-pound ratings on all screws and bolts vary widely with size and design, and should be determined before installation.

Sealing the ceiling panels is likewise important. The same compound used in manufacturing is the preferred material. Whatever you use, be sure it won’t adversely react chemically with what’s already up there.

If entire panels must be replaced, now may be the time to try translucent ones (if you haven’t already). The fibreglass panels add light to dark interiors. However, they also raise interior temperatures, which may be a minus if you haul cargoes that can be damaged by heat.


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