Boat Trailer Wheel Bearings Check

When was the last time the wheel bearings on the boat trailer were checked? There are so many things to go wrong and they seem to wait until the most inopportune time to do so. When things fail, sometimes it’s not expensive, but other times it can break the budget. This is especially true of wheel bearings and the components associated with them. Taking the time to inspect wheel bearings will save money and heartache throughout the fishing season. Wheel bearings have three major things we need to keep track of; adjustment lubrication, and water intrusion. Adjustment is an easy check, so let’s start there.

Wheel Bearings Adjustment Check

Make sure the trailer wheels and/or the tongue jack wheel are chocked to prevent the trailer from rolling away while working on it. I use a “dolly wheel donut” which the wheel sits in when parked. I also connect my trailer to the truck, so I am sure it isn’t going anywhere. Once everything is secure, jack up one side of the trailer. If the boat is on a newer trailer with torsion axles, do not jack it up by the axle. On those trailers, use the frame to jack it up or risk damage to the axle unit. Before putting hands against the tire tread make sure it doesn’t have metal, glass or even a steel belt coming through the tread. Grab the tire with both hands at 180 degrees apart and try to rock the tire on the spindle. There should be very little movement. If there is appreciable movement, bearings need to be checked for damage and tightened. There are several places here in the UB Garage blog describing how to do this, or have the bearings checked by a professional.

Wheel Bearings Lubrication

If the wheel bearings fail while travelling it can be a real problem. Sometimes, due to age or lack of lubrication, the wheel bearing can lock up.

Locking up is when the bearing generates enough heat to warp the bearing housing and the bearings race and hindering the normal function. As the heat continues increasing, the housing and bearings become one, IE “Locked Up”.

When the bearing and race are locked up, it causes the race to spin around the axle or inside the drum or rotor. Either way causing damage. Depending on the level of damage a whole new axle may be required. As a minimum, after a lock up, a drum/rotor, bearings, and seals will need replaced. Sometimes, if caught soon enough, we can get away with just replacing the bearings and races on an axle. However, it can be a major job to get the inner race off the spindle, don’t ask me how I know.

Losing lubrication can make a wheel bearing fail quickly. Most common wheel bearing grease leaks are because of a wheel seal puncture or failure. If the trailer has brakes, these leaks are not as readily noticeable until several miles have passed. Typically, these excess miles also cause brake parts to fail. Without a brake caliper or drum, a grease leak is easily identified by a simple walk around of the boat. On a trailer without brakes, there is grease inside the fender, trailer frame, back of the tire and sometimes even the side of the boat.

Once the bearings lose their lubrication it’s all downhill. Two metal parts without lubrication rubbing together create a tremendous amount of heat. The rollers start breaking down and the bearing races are also pitting and warping. When I find a condition like this I don’t bother washing the bearing and looking to see if they are repackable. They are headed Direct to File 13, the circular file drawer, or The Trash Can. New bearings, new races and seals are a small price to pay for uneventful travel to our fishing honey hole.

Wheel Bearings Water Intrusion

Water intrusion is easy to determine after removing the bearing dust cap or Bearing Buddy while checking the condition of the grease. With conventional wheel bearing grease, the grease will become muddy or chocolate milk looking after the water is mixed with the grease. If a marine grease was used, discoloring doesn’t happen except in extreme cases. Most marine grease are designed to stay separated from water. So, if there is a water leak expect to see both water and grease under the cap or Bearing Buddy.

If there is evidence of water intrusion, it’s time to replace the seals and repack the bearings. Pull the bearing and clean them really well and blow dry with air or allow to dry in the sun. Never, spin the bearing with air to make the cool whining sound. This is an unsafe practice which can cause serious personal damage. Clean out the hub, check the bearing races, repack and reinstall. Don’t forget to put additional grease in the hub between the bearing races. Refill bearing buddies, if used, so there is positive pressure inside the hub. This helps keep the water from getting in.

Safe travels!

Kris