We’ve all seen the sad image of a trailer alongside the highway, missing a wheel & hub while the unfortunate owner is searching for new wheel bearings on a weekend and far from the nearest town. This should never happen to you if you follow a few easy rules. For example, I’ve been driving cars and towing trailers for over 50 years and never experienced a wheel bearing failure. During my auto repair days it was not uncommon to see front wheel bearings with over 300,000 miles on them and they were still going strong.
Two simple things make the difference between getting to the river on time or sweating in the hot sun trying to remove a seized wheel bearing – adjustment and lubrication. A loose bearing wears prematurely while a tight bearing generates excessive heat which breaks down the grease and eventually fails.
Bearing Adjustment
A loose bearing wears prematurely while a tight bearing generates heat and fails. Jack up your trailer and wiggle each tire from side to side. There shouldn’t be any free play yet the tire should spin freely.
If there is free play, remove the dust cap and cotter pin then tighten the large castellated nut until snug then spin the wheel – this will seat both bearings in their races.
Loosen the nut about ¼ of a turn then re-tighten just enough to remove any free play. Since there is only one hole in the spindle for the cotter pin, you have to use your judgement on how much you tighten the castellated nut.
Personally, I tighten the nut finger-tight then look to see if the hole in the spindle is visible through one of the notches in the nut. If not, I slightly tighten the nut until the spindle hole appears and re-install the cotter pin.
Lubrication
Older axles require that you remove the wheels and hubs and drive out the grease seal so that you can remove the bearings, wash them in solvent, and re-pack them with fresh grease. Definitely a time consuming & dirty job.
More modern axles are manufactured to make lubrication a breeze. Look at the dust cap on the hub, if there is a rubber plug in the center of the dust cap, you’re in luck.
Jack up the trailer so that you can spin the wheels then remove the rubber cap. Attach a grease gun to the grease fitting and start pumping. Keep pumping until all the dirty grease has been pushed out by the fresh grease.
I use a high-quality bearing grease that is bright red in color so it’s easy to see when the old dark grease has been replaced with fresh grease. As you are pumping the grease, spin the tire occasionally to work the fresh grease through the bearing rollers.
Once all the old grease is out of the hub, replace the rubber cap and you are done for the year.
I do this once every year in the early spring and my 16 year-old trailer bearings are still like new.
