The bearings in a boat trailer wheel are vital to the proper operation of the trailer, and thus to the safety of its cargo. Distributing the load correctly, and maintaining the mechanical integrity of the wheel itself, requires regular lubrication. However, it can be difficult for one just starting out, to know precisely how often to add grease (the most effective type of lubricant) to the wheel bearings. The following are three criteria to observe when determining how often to regrease your bearings.
1. The Wheel's Size
The smaller a wheel, the more friction is put upon its bearings, because it moves more. The typical rule of thumb is that on the average, a trailer wheel's bearings should be regreased every 2,000 miles at least. If your trailer wheels are below the industry standard size, they should be regreased more often.
2. The Wheel's Environment
If your wheels are in a clean, dry environment, the 2,000 miles rule is perfectly valid. However, if you frequently take them to the marina (and submerge the wheels), this figure needs to be modified. Also, if you operate your trailer in a dusty environment (such as the Southwest), you also need to regrease more often, because of the preponderance of foreign materials which tends to clog the existing grease.
3. The Wheel's Age
Older wheels require more care than younger ones do. If your wheels are more than 10 years old, regrease them more often than 2,000 miles. If they have two or more of these criteria, go ahead and regrease them every 1,000 miles, or every six months.