By Pat Piper

Advice from our TRAILER ASSIST professionals.

Photo of a truck towing a boat

The most common service call we get is for a failed wheel bearing. When this occurs at high speed, the wheel can lock and come off, the axle hits the ground, and it can lead to catastrophic accidents. This doesn't happen to the guy pulling a 20-foot Boston Whaler as much as it happens to the guy pulling a tri-axle trailer with a big boat, who is more cavalier about maintenance. We commonly hear, "I wasn't going that far."

Check your bearings before you leave home. If you’ve got Bearing Buddies (bearing protectors) and they look dry, that means you need to add some grease. Keep a log of the mileage when grease is added.

Failed bearings are what we see all the time. I see it with trailers that have sat unused and then are taken on the highway, submerged in saltwater, and nobody takes a moment to maintain them by adding grease. One piece of advice I have: Pull your trailer for about five miles, pull off the road, turn off the engine, and put your hand on each trailer hub. If it feels hot, that's a sign there'll be a bearing failure soon or that more grease needs to be added.

Bearings are the main reason we're called to make a roadside repair. Customers don't understand the importance of doing preventive maintenance by replacing and inspecting bearings. People usually know what to look for with a tire because they do that with their tow vehicle. They can relate to having good tread depth because, unlike bearings, it's visible. 

Always Carry...

Every trailer needs a tool kit that includes:

Trailer tool kit

  • Wheel chocks to secure the trailer when changing tires
  • Extra line (for tie-downs and winch)
  • Extra trailer light bulbs
  • Bearing grease and a grease gun, cotter pins, wheel bearings and seals — although a spare tire/hub with pre-greased bearings is a time saver
  • Road flares or triangular highway emergency markers to set out to warn traffic of your location alongside the road
  • Flashlight
  • WD-40 — can be used to spray trailer wiring contact points
  • Paper towels and plastic bags to put the dirty towels in until you get to a trash can
  • Replacement lug nuts
  • Spare section of a brake line in the event of a break — can be used to cover existing line and secured with hose clamps
  • Screwdrivers (Phillips head and standard), socket wrench, hammer
  • Duct tape and electrical tape
  • Jack and lug wrench

Make sure to carry a jack and lug wrench that will work on a trailer. The jack and lug wrench that came with the tow vehicle may not work on your trailer so take the time now to look at this, rather than when you're on the side of the road. If using a hydraulic bottle jack, a block of wood between the top of the jack and the trailer frame will deter scratches on the frame that could open the door to corrosion. It's also helpful to have a small piece of plywood to use as a base for the jack in the event you have to use it on unstable ground.

— Published: Summer 2013

Top Five Reasons for Calls

  • 44% Flat Tires
  • 19% Bad Bearings
  • 12% Axle Problems
  • 12% Miscellaneous Vehicle and Trailer Problems
  • 2% Trailer Brake Problems


If boat trailer bearing grease looks white, this means water has gotten into the bearing assembly

If you can't back up a trailer with disc brakes, 90 percent of the time this means the reverse solenoid on the actuator is stuck. This occurs most commonly when backing up a hill. Adding some grease may help. Sometimes, a screwdriver can be placed in a hole in the coupler on the driver's side, just behind the locking latch. This will keep the brakes from engaging. However, once the trailer is backed into position, remove the screwdriver; otherwise, you have no brakes when underway on the highway. Other causes include the tow vehicle's reverse lights not working.

If the actuator's master cylinder is full but you have no braking power, there's air in the system.



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