Bearings & Seals
We highly recommend having your bearings and seals maintained at least once a year to ensure proper performance. Bearings limit the friction and wear on your wheel assemblies, as well as keeping them relatively cool. Any notice of vibration, strange grinding noises or even grease in your fender well may be signs of failed bearings or their seals.
If you're worried about your bearings, jack one side of your trailer up and ensure the wheel spins freely without any grinds or resistance. Grab the tire from the top and bottom and check for any play or swivel in the wheel. If any of these tests cause concern, it's a good idea to have your bearings repaired or replaced immediately.
Brakes are also very important to have regularly maintained and should be inspected often. Just because your brake lights work doesn't mean the brakes are engaging properly. Before a trip, take a couple minutes driving and braking periodically and check to see if the braking assemblies are warm to the touch. If cool, there was no friction applied to the wheel.
Further inspection requires jacking up one side and visually checking the brakes. Look for any suspicious corrosion on drums or discs, depending on the type your trailer has. Any thin or worn drums need replaced, and uneven could mean a number of things require repair. Check rotors for any warping or cracks, and brake pads should thick and tightly secured within the caliper. If you have hydraulic brakes, check your brake lines and master cylinder for any leaks. Also inspect your brake fluid reservoir located in the tongue coupler for any rust or dirt. If any damage has occurred, your system will need to be bled and refilled.
It's pretty easy to notice if something like a light bulb isn't working, but not always so easy to find the problem. No matter what application it is, it's best to inspect your connector first. Look for any corrosion and any loose or damaged wires. The next step would be to check your towing vehicle's fuse box for any damaged fuses that need replaced. Beyond that, wires under or behind the wall panels may have been damaged or jarred loose and can be very difficult to reach.
Couplers & Jacks
Often overlooked, trailer couplers and jack stands are still essential to properly maintain. Remember, the only contact between the vehicle and trailer is the tongue coupler. This means any tongue weight or turning friction is plausible to cause excess wear on both the coupler and ball mount. Occasionally inspect under the coupler and look for rust or damage that look suspicious. After the trailer is supported by the vehicle, make sure the latch isn't seized or misplaced.
Over time, jack stands or jack wheels become increasingly difficult to crank and can lead to complete seizing. It's always good to keep the jack's threading and gears well-lubricated. These are often hard to reach or reassemble, so repairing or even replacing a stiff jack is recommended.