How Trailer Maintenance Works

Trailer in bad shape
You think you've got a tough job ahead of you getting your trailer back in shape? It could be worse.
Ed Freeman/Getty Images

That trailer of yours has definitely seen better days. Look at it over there; are those weeds growing around its tires? Wait, is it missing a tire? Face it, buddy: Your trailer is falling apart.

You loved it once. You got it as a present for your birthday years back, and you thought it was the shiniest, coolest, most practical thing you'd ever seen. Now, it sits like a depressed, neglected hulk in the driveway. You and your trailer need to spend some quality time together again.


Sure, you could take it to a specialist. There are plenty of business owners making a good living by maintaining other people's trailers. But what better way to pass a pleasant afternoon than getting your trailer back up to snuff? It's going to take a little bit of elbow grease and some time, but with our advice you'll have your trailer back into road-ready condition.

In this article, we'll look at ways to keep your trailer maintained. You'll learn about what to use when washing it. We'll teach you what parts to keep lubricated and how to do it. We'll also cover maintaining the tires and inspecting the lighting system. In no time, you'll be able to get your trailer back in shape. Read the next page to get started.


Washing a Trailer

Power washer
This is precisely the kind of power washer you don't want to use on a trailer with an automotive finish like this one has.
Greg Nicholas/iStockPhoto

For starters, we'll give that old trailer a nice washing. It's a good idea to keep your trailer clean, especially if you have an enclosed trailer. Often, these trailers are given an auto finish with several coats of paint and sealant. As such, you should wash these trailers with warm water, using soap that's specially formulated to take it easy on auto finishes. If you don't have a trailer with an automotive-grade finish, soapy fresh water will suffice. Use a regular hose to rinse off; high-powered pressure washers can damage the finish and degrade the trailer body. Be sure to spend time cleaning the reflective plates and lights to let them shine. Don't forget to rinse off the undercarriage, as road dust can accumulate and degrade moving parts.

If you have a boat trailer, you must wash it after every use, especially if you use it around salt water. Salt water can accelerate corrosion, so be sure to pay extra attention to the wheels, suspension and brakes. Salt water can collect on these parts and evaporate, leaving a salt residue that can wreak havoc on metal.


Look for rusted parts and areas as you wash. Sand away any patches you find with sandpaper or steel wool. After you've finished washing and the trailer has dried, touch up the areas with rust-proof paint. Once the paint dries, apply a healthy coat of wax on your trailer's painted metal parts. You should do this even if your trailer didn't require any touching-up. Keeping your trailer waxed sounds a bit over the top for all but the nicest models, but it protects metal parts from the elements and prevents rusting.

As you're washing, you may realize you're facing a challenge: Trailers can be awfully tall. Not to worry, there are plenty of tools on the market to help you get every square inch of that trailer clean. Telescoping wash brushes and chamois can make your life a lot easier. Of course, there's also something to be said for a sturdy, non-slip step ladder with good tread on each step.

The old trailer looks nice and shiny now, doesn't she? Unfortunately, it's time now to get down and dirty. Read the next page to learn about keeping your trailer properly greased and lubricated.



Keeping Trailer Parts Greased

Wheel bearing
A cross section of a wheel bearing. Each inner bearing should be removed, cleaned, dried and greased before being reinstalled.

Dirt is your trailer's biggest enemy. Once particles of dirt and dust get into your trailer's moving parts, it can cause friction and break down. Keeping your trailer's parts greased can help keep joints and axels moving smoothly. Before you take it back onto the road, do a little greasing first.

Pretty much any part of your trailer that's designed to move in some form or fashion or comes in contact with other parts should be kept lubricated to prevent corrosion and friction. Features like a winch, ball hitch, springs and tongue jack all require lubrication and you should keep them greased throughout the year. It's a good idea to make lubricating your trailer's moving parts an important part of your routine before each long trip.


It's important to keep all moving parts lubricated. One of the most important parts are the wheel bearings, the cylindrical rings that connect the wheel to the axle and allow for the wheel's free rotation. Since the wheels are extremely important to your trailer's ability to function well, it's important to maintain your wheel bearings. And since the wheel bearings and axles are a metal-on-metal combination, it's important to keep them well greased to prevent friction and potential wheel damage.

The wheel bearings are packed with inner bearings that allow the wheel bearings to move as a whole. Part of any trailer maintenance should include cleaning and greasing the wheel bearings for each wheel. We've included an in-depth guide to properly cleaning your wheel bearings on the Lots More Information page, but here's a quick run down of what you can expect. It may sound like a pain, but, again, it's extremely important to maintain your wheel bearings.

You'll first have to remove your tire and any hardware holding your wheel in place on your axle. You'll find your wheel bearing on the wheel hub, and it should be easily removed after removing the hardware holding it in place. You'll want to soak the wheel bearing in gasoline to loosen grime and old grease. Remove the old seal, then the inner bearing. Thoroughly clean the inner bearing and the wheel bearing as a whole.

After the parts are completely dry, replace the inner bearing and seal the wheel bearing. Gently add grease to prevent breaking the seal, and wipe off any excess grease. Now's also a good time to grease the axle. After you reinstall the wheel bearings and the wheel, move on to the next one.



Trailer Tire Maintenance

Trailers often have special tires that prevent swaying during towing. Never mix and match tire types on trailers.
Phil Augustavo/iStockPhoto

Since the function your trailer performs is based largely on its tires, it's a good idea to keep your trailer tires well maintained. In many cases, especially with large trailers, the added weight the tires support even when stationary can cause trailer tires to wear out significantly faster than the tires on your coach vehicle.

If your trailer's been sitting around unused for a while, it's a good bet the tires could use inflating. Using your trailer often can obviously lead to loss of air pressure, but tires also lose pressure when not in use. All tires leak air over time, and so keeping an eye on your air pressure is essential to keeping your trailer properly maintained.


The reason for maintaining proper air pressure in your tires is simple: Taking a trailer fully loaded out on the open road with under inflated tires is extremely dangerous. The friction created when the rubber meets the road can cause degradation of your tires. This situation can lead to a blow out, which is the last thing you want to happen to a trailer hitched to your car and traveling at high speeds. Even if a blow out doesn't occur, improperly inflated tires flatten under the strain of an overly heavy load. This can create another dangerous situation, one where swaying of the trailer can occur.

Before inflating your tires, check the manufacturer's suggested pounds per square inch (psi) of inflation. It should be listed in the owner's manual for your trailer. You should also note if your trailer's tires call for a high psi when carrying heavy loads. If so, be sure to observe this when you inflate your trailer tires.

Before every trip, check your trailer tires for wear. It's recommended that you replace your trailer tires every three to five years. When replacing tires, make sure the ones you purchase match the ones you already have, if you're not buying a complete set. It's a good idea to shell out the extra cash to replace all of your trailer tires at once, as even good tires are worn to some extent and the addition of a new, unworn tire can lead to handling difficulty when towing. Some manufacturers make tires that are specially designed for trailers. Bias ply tires are stiffer than the radial tires found on most cars and trucks. This stiffness helps to protect against sway, since the tires don't give from side to side as much as more pliable auto tires can. When you store your trailer, drape tarps over them to protect against sun damage, which can cause cracking and splitting.

Okay, you've gone ahead and spent the money to replace your trailer's tires. You've got them properly inflated and you're good to go. Your trailer's almost back to mint condition. Read the next page about checking your trailer's light systems.



Checking Trailer Light Systems

rear of trailer
Ensuring your trailer's light system functions properly is a big part of trailer maintenance.
Marcus Lindstrom/iStockPhoto

Have you ever driven down a dark highway and passed another vehicle that didn't have its lights on? Chances are, you thought the other driver was a jerk, and you were right. It's a bad idea across the board to drive with your lights off or out of order. This is true for cars and trucks, as well as trailers.

Keeping your trailer properly maintained entails keeping your trailer's lights in proper working order. This is especially important, as most states require trailers have functioning brake and tail lights, as well as turn signals and license plate lights. The wiring for all of these lights should be placed together as part of your trailer's lighting system. In most cases, all wires converge at a central plug that connects to a wiring socket powered by your coach vehicle. When maintaining you trailer, take some time to follow the wires on both your trailer and your coach vehicle to ensure the wiring insulation is in good shape. Keep an eye out for corroded, worn or cracked spots. If you come across any weak points in the wiring, wrap it several times with electrical tape to insulate it.


While your coach vehicle's engine is turned off (and your lights in the "off" position for good measure), you must clean off your electrical connectors. Get rid of any road grime or other type of build-up. Once clean, dab on a little bit of dielectric waterproof grease -- this type won't conduct electricity and keeps moisture out of your electrical connections. You can also dab this type of grease around light bulb sockets and other places where moisture can get into your electrical system.

Now that you've taken steps to protect against an electrical failure out on the road, your lighting system should theoretically work. Theory's all well and good, but the road calls for you to ensure the lights are working in practice. This can be a bit tricky with just one person, since it requires one person to turn on the lights and one to visually confirm they're functioning properly. Some lights, like the turn signal, can be left on while you wander to the back of the trailer to make sure it's functioning. Others, like brake lights, are a little trickier. It's a good idea to grab a buddy, family member or neighbor for a few minutes to help you; the job will go by more quickly and easily than if you try it alone.

Test each of the lights in the system, one at a time. Start with the tail lights and license plate lights. Next, test the turn signals, and finally the brake lights. Ask your helper to confirm each is working before moving on to the next light. Replace any bulbs that may have burned out and address any larger electrical problems before taking your trailer out on the road.

Congratulations! Your trailer is back in ship shape and ready for action, with just a little effort and a few dollars on your part. It's time to hit the road.

For more information on towing and other related topics, visit the next page.



Trailer Maintenance: Lots More Information

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More Great Links

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  • "Trailer tires." Hitching Up. Accessed October 27, 2008.
  • "Trailer towing: being equipped for safety." National Highway Traffic Safety Administration. April 2002.
  • "Wheel bearing description." Car Stuff. Accessed October 27, 2008.
  • "You and your boat trailer; what you need to know." South Australia Department for Transport, Energy and Infrastructure. June 2006.