Should you get a trailer with greased bearings, or oil filled hubs?
You’re running down the highway at 65-mph with your boat in tow, it’s zero-dark-early in the morning, and the last thing you need right now is a boat trailering disaster. Suddenly, there’s a strange vibration in the steering wheel. Then the grinding sound of metal on metal drowns out the pre-fishing tunes on your truck radio. You move your foot from the gas pedal to the brake, glance in the sideview mirror, and see a cloud of smoke so thick you’d think you were in SoCal during peak fire season.
Pull over, quick! Your wheel’s about to fall off, because you just blew out a trailer bearing.
Have you ever lived this trailer-boating nightmare? It’s not unlikely – many of us have experienced it one time or another, and dedicated trailer boaters pay a lot of attention to their bearings’ condition and regular maintenance. While we’re all used to dealing with grease bearings, oil-filled bearings have become a more common option. But which is really better for trailer boaters? Shocker alert: the manufacturers of each product say theirs is best.
All Oiled Up
In some ways, oil-filled bearings may in fact be significantly better than traditional grease bearings. The biggest advantage? Their manufacturers claim you can trailer up to 40,000 miles without changing the lube, as opposed to 3,000 to 4,000 miles generally being considered the norm for grease bearings. Many users back this claim up. At the same time, oil-filled bearings reduce bearing wear and friction, and are easily visually monitored via a see-through cap on the hub.
Of course, there are some down-sides to oil-filled rigs, too. One of the more common issues is bearing damage that occurs due to swiping a curb or obstruction. The housings are plastic, and it you smack one, they’ll crack. Then the oil all leaks out and you won’t make it very far before the grinding sounds and smoke start. Another problem with this type of bearing is that if your trailer sits for long period of time without use, all the oil sits at the bottom and the top half of the bearings are exposed to air. Condensation can then form in the hub, which leads to corrosion and/or pitting, which then ultimately leads to bearing failure. This problem can be solved by rotating the tires every week or two. That may not be a huge deal, but yippie – as if you didn’t already have enough to keep track of in your life, right?
On the flip side of things, while regular old grease bearings do require regular service at aggravatingly short intervals, it’s service that many of us have performed a million times. We’re used to the job, won’t hesitate to make it happen, and can do it on the side of the road when and if necessary. But few of us know how to deal with oil-filled hubs, which means you’ll probably want to pay a pro to install them and work on them. Plus, remember that grease bearings are the norm across the country. Parts can be found for them anywhere, any time, with ease. Not so with the oil-filled variety. If you experience a failure in an area where there aren’t any nearby dealers, your rig could be disabled for a day or three.
The greatest advantage to grease bearings, however, is probably their stubbornness. When a bearing first starts to go grindy it will often keep on spinning long after the problem arises, allowing you to make way for a repair shop or get back to your driveway instead of leaving you on the shoulder. Oil filled bearings usually go in a more catastrophic manner—everything’s running just fine, then a failure forces a sudden and complete stop.
Now let’s answer the original question: which system is superior? Nah, let’s not – as usual with all things related to boating, there are trade-offs involved with each choice. If you trailer on a professionally obsessive-compulsive fish-head level and put countless miles on your trailer each and every weekend, holiday, and (cough, cough) sick day when the bite’s hot, oil-bath bearings are an excellent option. But if your personal trailering schedule is more erratic and your boat doesn’t move for weeks at a time, you’ll most likely want grease in your hubs. The exception will be if you’re a DIY type of person who’s been towing with grease for years, you want to continue doing the maintenance and repairs on your own, and you want to have the flexibility to perform road-side repairs yourself. In that case, sticking with the sticky stuff is a no-brainer.
Will the manufacturers of oil-bath bearings agree with the above assessment? Probably not. How about the grease-makers? Uh-uh. But we think that after considering all the facts, those of us that don’t have a dog in this race will reach the same conclusion.