RV Wheel Bearing Maintenance: Grease, Seals and Tools to Own

Bearing service needs the right grease, matching seals and a few tools, and it also needs the honesty to hand brake and damage work to a shop. Here is the shopping list and the line.

To maintain RV wheel bearings you need the grease and seals your axle maker specifies, a small set of tools and your axle manual open beside you. Bearings, seals and brakes sit in the same hub, so a careless job can contaminate brakes or leave a wheel at risk of coming off. Buy for the jobs you can do correctly, and hand brake work, damaged parts and anything doubtful to a qualified shop.

This guide is about the shopping list and the boundary. For how bearing trouble connects to tire wear and failures, see our guide to tire care and safety, and for the tire-side roadside gear see building a spare tire kit.

Start With Your Axle, Not the Parts Store

Find the axle maker and model on the label or tag, then find that maker's manual. Dexter's Light Duty service manual, for example, describes three hub styles: standard grease-packed bearings, E-Z Lube hubs with a fitting for adding grease without removing the hub, and factory-sealed Nev-R-Lube bearings. They are serviced differently, and some hubs use oil rather than grease. Buying parts before you know which you have is the usual way to end up with the wrong kit.

Grease: Match It, Do Not Mix It

Dexter's manual says to use a lithium complex grease with extreme-pressure and corrosion inhibitors, and warns not to mix lithium, calcium, sodium and barium complex greases. For other makers, the manual names the grease. The practical rules are simple:

• Buy the type your manual names, and do not guess from a label that says "wheel bearing" or "multipurpose".
• Do not mix families. If you do not know what is in the hub now, ask the shop or clean out the old grease as the manual describes.
• Use a hand-operated grease gun. Dexter advises against pneumatic grease guns because they can force grease past the seal.
• Repack after water. The manual says bearings need repacking after being immersed in water.

Seals: The Small Part That Protects the Brakes

A seal keeps grease in and water out, and it keeps grease off the brake parts. Dexter's manual says to inspect the seal every time the hub comes off, replace it if it is nicked, torn or in doubt, and use only the seal types the manual specifies. It also says to drive a seal in evenly and straight, not by hammering on it directly, and not so far that it touches the inner bearing.

When you order, match the seal to your hub and spindle from the manual or a parts list, not to what looks similar. On E-Z Lube axles, the manual says to replace the seals before lubricating the bearings if the hub has been removed.

Tools Worth Owning

What the Job Involves, and What to Watch For

This is an outline of the shopping decisions, not a how-to. The manual gives the steps. Several points in Dexter's manual deserve emphasis because mistakes are costly:

• Support the trailer only at manufacturer-approved points, never on the axle or suspension.
• Failure of wheel-end parts can cause a wheel to detach, with a loss of control and serious injury as the possible results.
• Replace a bearing that shows pitting, spalling or corrosion, and replace the cone and cup as a set.
• Never spin a bearing with compressed air.
• Keep grease and oil off brake linings, drums and magnets.

Signs It Is Time for a Look

Do not wait for a fixed interval alone. Check a hub after the wheels have been under water, because the manual says bearings must be repacked after immersion. Other reasons to stop and investigate include a wheel that feels hot after a drive compared with the others, a grinding or rumbling noise, grease on the inside of the wheel or on a brake drum, or play when you rock the wheel by hand. Any of these means the trailer should not keep traveling until someone qualified has looked at it.

Common Mistakes

• Greasing by habit. Adding the wrong grease to a hub that holds another type can cause trouble, and sealed bearings need none.
• Reusing a damaged seal. It is cheap compared with a brake contaminated by grease.
• Pressing in a seal crooked. Seat it evenly, as the manual describes.
• Using a shop air gun on a bearing. Never spin it with compressed air.
• Buying a generic bearing kit by trailer length. Match the parts to the axle, spindle and hub.

Buying Tools New or Used

Sockets, breaker bars and a hand grease gun are fine to buy secondhand if they are clean and work smoothly. A torque wrench should be in good condition and stored as its maker advises. Avoid used jacks and stands with bent legs, cracks or missing pins. Bearings, seals and cotter pins are parts you should buy new.

What to Leave to a Shop

Bearing service is a reasonable job for a careful owner with the manual and the right tools. A shop is the better choice when:

• Brakes are involved. Dexter's manual gives the standard for lining wear, contamination and replacement in pairs, and it also notes that older linings may contain asbestos, so dust should be avoided.
• Parts are damaged. A scored spindle, a cracked hub or a bearing you are unsure about is not a guess.
• A wheel wobbles, runs hot, makes noise or leaks grease. The cause may be more than a dry bearing.
• You lack the space, stands or a torque wrench. The right setup matters.
• You are unsure at any step. The manual itself says to contact a repair facility or qualified mechanic when a problem cannot be resolved.

Our RV tool kit guide covers the general tools, and the blowout prevention guide covers the other half of keeping wheels on the road.