For most RV owners, wheel bearing service is usually based more on time and usage conditions than on mileage alone. A common rule of thumb is to inspect and repack bearings about once a year, or every 10,000 to 12,000 miles, whichever comes first. If the RV sits for long periods, gets used in heavy rain, travels on rough roads, or has been immersed in water at all, it is smart to check them sooner. Trailer bearings especially can go a long time quietly until they don’t, and by then the damage can be expensive.
If you just bought a used RV, I would not assume the bearings were serviced recently even if the seller said they were. Unless you have clear records, it’s worth treating them as overdue and getting them inspected. That gives you a known starting point. A fresh service also lets you check the grease condition, seals, spindle wear, and whether the bearings were packed correctly in the first place. A lot of bearing failures come from lack of grease, contaminated grease, or seals that have already started to leak.
There are also situations where annual service may not be enough. If you tow in hot weather for long distances, carry heavy loads, or do a lot of mountain driving, the bearings are working harder. In those cases, many owners like to inspect them more often, especially before a major trip. On the other hand, if you have a newer RV with sealed hubs or EZ lube-style fittings, that does not mean you can ignore them forever. Those systems still need inspection, and over-greasing through a zerk fitting can actually force grease past the inner seal and create a mess or a failure.
A few warning signs should make you stop and inspect right away. Excess heat at one wheel hub after a drive, rumbling or grinding sounds, play in the wheel when you rock it by hand, or grease leaking behind the wheel are all red flags. If a hub feels noticeably hotter than the others, that wheel should be checked before you keep towing. It’s also a good idea to check torque on the lug nuts and inspect the brakes while the hub is apart, since that is already part of the same area.
If you want the safest approach, start with annual service, then shorten the interval if your RV sees hard use. For a used RV with unknown history, servicing the bearings now is usually cheap insurance compared with replacing a hub, spindle, or wheel assembly later.
