Daily Archives: October 1, 2015

The Keys To Fifth Wheel Safety

We’ve all read a headline or two that said something like “Runaway Trailer Hits Passenger Car.” While we may not know the details, we’re given enough information to know that somehow a trailer separated from its tractor and caused an accident. Don’t let that headline be about you.

The fifth wheel is the unsung hero. It’s easy to forget that it plays a key role in truck safety, and like any safety-related component, it needs to be in good operating condition. This is the piece of equipment that keeps the trailer attached to the truck. The last thing you want is to see it disconnect and go flying across the road behind you.

Preventative Maintenance

So you know how important the fifth wheel is, but how do you maintain it? Most fifth wheel manufacturers recommend for a complete maintenance every 30,000 miles or so.

The main thing to remember is that you need to lubricate it through all four seasons. This should give you ample time to inspect it at least four times throughout the year. We recommend a quarterly schedule that parallels other maintenance functions.

If you choose not to maintain a schedule of this frequency, you should at least be cleaning the locking mechanism every 60,000 miles or so. Waiting any longer could introduce an unnecessary element of risk.

What to Do

Wondering how to properly maintain your fifth wheel? We can tell you it’s about more than just making sure it’s lubricated. You also need to make sure you are thoroughly checking it over for damage.

First, you must degrease it with a degreasing compound or steam cleaning machine. Since grease attracts dirt and debris, the only way you will be able to uncover any hidden damage is by fully washing away the grease.

Make sure you remove all of the grease, including buildup around the lock jaw, throat and pivot joints. Once the grease is clear, look for cracks, broken welds and damaged or missing components. Once you’ve completed the inspection, regrease the fifth wheel with a thin coat of 90-weight lithium EP grease.

Manage Through the Seasons

Keep in mind that the changing seasons will affect your fifth wheel differently. People tend to add grease throughout the year, and while you may be able to get away with that in the summer, grease buildup during the winter months can cause some serious problems. Old grease buildup can freeze and interfere with the locking mechanism.

And although the springtime may seem the most benign of seasons, it’s no time to slack off on your fifth wheel maintenance, especially after a harsh winter. Lube gets washed or worn away in moist frozen or rainy conditions.

Over the winter, de-icing materials can be brutal on fifth wheel components. When moving parts begin to get rusty or corroded, the whole system can be thrown off, and when the timing of coupling and uncoupling is thrown off, it is more difficult to snap the tractor in place.


The fact is this: Not properly maintaining your fifth wheel could result in catastrophic injury or death. Not to be fatalistic here, but it’s the truth.

Here are some quick step-by-step keys to making sure your fifth wheel stays in good working order:

  • Clean dirt, debris, and grease from the fifth wheel. Also clean the mounting brackets, lock jaw, throat and pivot joints.
  • Thoroughly inspect each component for cracks, damage or premature wear.
  • Verify the thickness of the bracket liner. If it is less than 0.125 inches at the top, replace it. For standard-duty applications replace the liners every 300,000 miles. For heavy-duty applications, cut that in half.
  • Inspect the bracket pin bolts to make sure they are properly secured in the locking tabs.
  • Replace parts (if necessary).
  • Apply a new layer of water-resistant lithium grease. Make sure the kingpin lock is properly lubricated.
  • Check operation, test the lock, and verify complete closure.

So, next time you are setting up your maintenance schedule, make sure you pay proper attention to the one component that ensures your trailer doesn’t go flying off the road: The fifth wheel.