Wheel Bearings,
Brakes & Tires

Annually or Every 12,000 Miles — Whichever Comes First

That's the Dexter and Lippert manufacturer specification. Grease breaks down over time regardless of mileage — so a trailer that mostly sits still still needs annual service. Heat cycling, moisture, and storage conditions all degrade grease without a single road mile on it.

If you've bought a used RV and don't know when the bearings were last done, treat them as overdue. Don't assume the previous owner kept up with it.

• Service annually or at 12,000 miles — whichever arrives first
• Unknown service history on a used unit means do it now, before your first long trip
• Low annual mileage does not exempt you from annual service — time-based grease degradation is real

Disassemble, Clean, Inspect, Repack — In That Order

A proper bearing service is a full disassembly. The hub comes off, all old grease gets cleaned out completely, the bearings and races get inspected, and fresh grease goes in by hand before reassembly. The seal gets replaced every time — it's cheap insurance.

Reassembly torque matters. Over-tightening preloads the bearing. Under-tightening allows movement on the spindle. Both cause premature failure. Follow the torque specification for your axle — it's in the manufacturer's documentation and it isn't a suggestion.

• Remove the hub completely
• Clean all old grease from the hub, bearings, races, and spindle
• Inspect bearing rollers and races for pitting, scoring, rust, or heat discolouration
• If replacing a bearing, replace the race with it — never run a new bearing on an old race
• Repack by hand — work fresh grease through the entire bearing cage before installing
• Install a new grease seal — don't reuse the old one
• Torque the spindle nut to the manufacturer's specification
• Do not pump grease through a zerk fitting and call it a repack — it overloads the hub and blows the rear seal into the brake drum

What to Check After Every Long Drive

Bearing problems build slowly. A quick post-drive check costs nothing and catches problems while they're still manageable.

• Hub temperature — after more than an hour of driving, hubs should be warm but not painful to hold your hand against. Excessively hot hubs are a warning. Compare side to side — a significant difference on the same axle means something is wrong on the hot side
• Uneven tire wear — scalloping or wear that differs between wheels on the same axle can indicate bearing problems or brake drag
• Pulling or wandering — a trailer that tracks poorly or feels loose may have bearing play developing
• Rumbling or grinding — a sound that changes with speed and goes quiet when you slow down is a classic bearing symptom
• A failing bearing gets worse quickly under load — don't keep driving and hope for the best

Inspect While You're Already in There

With the hub off for a bearing service, you're looking directly at the brake assembly. Don't put it back together without inspecting it. This is the most logical time to do it and it costs nothing extra.

Some RV brake assemblies are self-adjusting. Others require manual adjustment using a flat screwdriver through the access slot on the backing plate to turn the star wheel. If yours are manual and haven't been adjusted, the shoes are working from too far away from the drum and stopping performance is reduced.

• Check shoe lining thickness — thin, unevenly worn, or separated lining means replace the assembly
• Inspect the drum surface for scoring, heat cracks, or a wear lip at the outer edge
• Check the electromagnet face — a deeply grooved or worn magnet face reduces braking force
• Inspect wiring to the magnet for chafing, heat damage, or corroded connections
• On manually adjusted systems, advance the star wheel until the shoes are close to the drum without dragging when you spin the wheel by hand
• On self-adjusting systems, verify the adjuster mechanism moves freely and hasn't seized
• Grease-contaminated shoes cannot be cleaned and reused — replace them

The Controller Drives Everything

The brake controller in your tow vehicle tells the trailer brakes when and how hard to apply. Most owners set the gain once and never revisit it — which means it's often wrong for the actual load being towed. The right gain setting depends on trailer weight and load distribution and should be checked any time the load changes significantly.

Too little gain and the trailer pushes the tow vehicle. Too much and the trailer brakes lock up, causing sway or tire skip. Neither is safe.

• Test controller output at the start of each season — most units have a diagnostic display or indicator light
• Set gain by making a moderate stop from highway speed on a clear road — the trailer should brake smoothly without locking or feeling absent
• Test the manual override — pressing it should apply trailer brakes independently of the tow vehicle
• Inspect the 7-pin connector between truck and trailer — corrosion here causes intermittent or total brake signal loss
• More gain is not always better — a controller set too high under a heavy load can trigger trailer sway

Test It — Most Owners Never Do

The breakaway switch is a safety device required by law on trailers with electric brakes. If the trailer separates from the tow vehicle, the breakaway cable pulls the pin, activating the trailer brakes from the onboard battery and bringing the trailer to a stop independently.

The system only works if the battery is charged and the switch functions. A dead breakaway battery is a common find — and it means the one system designed to stop a runaway trailer does nothing.

• Test the switch annually — pull the pin by hand and verify the trailer brakes lock up
• Check the breakaway battery charge — it should read close to 12V; replace it if it's weak
• Inspect the cable routing — it should pull taut if the trailer separates, not get caught during normal use
• Confirm the pin is fully seated when hitched — a partially pulled pin can drag the brakes while driving
• A weak or dead breakaway battery must be replaced — this is a safety system, not optional maintenance

Tread Depth Isn't the Whole Story

RV tires fail from age as much as from wear. The rubber compound breaks down over time — hardening, cracking, and losing elasticity even when the tread looks fine. A tire that looks good at eight years old is not the same tire it was at two years old, regardless of how few miles are on it.

Most experts and the Rubber Manufacturers Association recommend replacing trailer tires at 5 to 7 years, regardless of appearance or remaining tread. If your trailer lives outside in sun and heat, lean toward the shorter end of that range. UV exposure accelerates rubber degradation significantly.

• Replace trailer tires at 5 to 7 years — don't wait for visible failure
• Tires stored outdoors year-round should be evaluated closer to the 5-year mark
• Don't assume used RV tires are safe based on appearance — always find the date code first
• Check the spare too — it ages the same as the rest even if it's never touched the road

How to Read the Date Code

Every tire manufactured since 2000 has a DOT code molded into the sidewall. The last four digits are what you need — they tell you exactly when the tire was made. The code is sometimes on the inner sidewall, so you may need to look at both sides or crawl underneath to find it.

A tire with the code 0822 was made in the 8th week of 2022 — February 2022. Simple math from there tells you how old it is today.

• Find the DOT code on the sidewall — look on both sides if you don't see it immediately
• Read the last 4 digits: first 2 are the week, last 2 are the year
• Calculate the age from today — if it's approaching 5 years, start planning for replacement
• When buying new tires, ask to see the DOT code — avoid tires that have been sitting on a shelf for more than a year
• Tires made before 2000 used a 3-digit code — if you see one, replace those tires immediately regardless of appearance

What to Look For During Inspection

Age-related tire failure gives warning signs if you look for them. Make a habit of walking around and checking the tires before and after every trip — and at least monthly during storage.

• Sidewall cracks — fine cracks or crazing in the sidewall rubber indicate UV and ozone degradation; the deeper or more numerous they are, the closer the tire is to failure
• Cracks between the treads — similar to sidewall cracking, this is a sign the rubber is drying out and losing flexibility
• Uneven or excessive tread wear — flat spots, scalloping, or wear that's heavier on one side points to a loading, inflation, or alignment problem
• Bulging or bubbling — any bulge in the sidewall is internal structural damage and means replace immediately, no exceptions
• Embedded objects — screws, nails, and debris can cause slow leaks that go unnoticed until pressure drops enough to cause a blowout under load
• A tire with any sidewall bulge should not be driven on — the structural integrity is already compromised