How to Repack Trailer Wheel Bearings: A Step-by-Step Guide
Wheel bearings are the part nobody thinks about until the hub is smoking on the shoulder of the highway. Repacking them is one of the most valuable pieces of maintenance a trailer owner can do, and the whole job is below — on video and in writing.
All 16 steps. The photographs are from the Trailer Safety Week article credited at the bottom of this page.
Why bearing service matters
Bearings let the wheel hub rotate on the spindle. Over time the grease breaks down, picks up contamination, or washes out. Heavy use, long trips and moisture all speed that up, which is why routine bearing service matters.
How often: every 6 months or 12,000 miles, whichever comes first, on every trailer. That is what NC Trailers recommends and it applies to boat trailers too — submersion is a reason to inspect seals more often, not a reason to stretch the interval. Some manufacturers publish a longer figure; we service at half that time. Check your owner's manual for your trailer's grease type and torque specifications.
Before you begin
This is a hands-on job that lives and dies on cleanliness. If you are not comfortable lifting the trailer, pulling the hub, or spotting worn parts, have a qualified technician do the work. Have the correct replacement grease seal on hand before you start, because the seal comes out during service and should not be reused.
Tools and supplies
- Jack and jack stands rated for the trailer, plus a lug wrench
- Pliers or side cutters for the cotter pin, and a flat screwdriver or cap removal tool
- Parts cleaning solvent or brake cleaner, shop towels and gloves
- High-quality wheel bearing grease approved for trailer use — boat trailers take marine-grade grease
- A new grease seal, and a hammer with a block of wood or a proper seal driver
- A torque wrench
Some hubs and cap styles need extra tools.
The 16 steps
Step 1 — Park safely and secure the trailer
Park the trailer on a level surface. Chock the wheels that stay on the ground and make sure the trailer is stable before you lift it. Loosen the lug nuts slightly first, then jack up one side and support it securely on jack stands. Never rely on a jack alone while you are working.
Step 2 — Remove the wheel
Finish removing the lug nuts and take the wheel off. Set it aside where it will not roll or pick up dirt on the mounting surface. That gives you access to the dust cap and hub.
Step 3 — Remove the dust cap
Carefully work the dust cap out of the center of the hub. Do it gently so you do not damage parts you plan to reuse. With the cap off you can see the spindle nut retainer, which is usually a cotter pin or a retainer clip.
Step 4 — Remove the retainer and spindle nut
Remove the cotter pin or retainer, then take off the spindle nut and washer. Keep the parts in the order they come off so reassembly is easier. On most trailer hubs the outer bearing can then be lifted straight out of the front of the hub.
Step 5 — Slide the hub off the spindle
Pull the hub straight off the spindle and be ready for its weight so it does not drop or drag across the spindle threads. Set it on a clean surface. The inner bearing will usually still be held in place by the grease seal at the back of the hub.
If the hub does not slide off with reasonable effort, do not force it. Too much force can damage the spindle. That is the point to stop and get professional service.
Step 6 — Remove the inner seal and inner bearing
Turn the hub over and remove the grease seal, then take out the inner bearing. The seal always gets replaced during service, it does not get reused. This part matters, because a worn or damaged seal lets grease escape and lets contaminants into the hub.
Step 7 — Clean the bearings, hub and spindle
Thoroughly remove the old grease from the bearings, the bearing races, the inside of the hub, the spindle, the washer and the nut. Use a suitable solvent and clean cloths. The parts have to be clean enough to inspect before any new grease goes on, because old grease hides wear, metal particles and contamination.
Step 8 — Inspect all components carefully
With everything clean, inspect the bearings and races for:
- Pitting, scoring, discoloration or rust
- Grooves or chipped surfaces
- Any sign of overheating or abnormal wear
Inspect the spindle for damage and corrosion as well. If a bearing or a race is damaged, replace it — bearings and races get replaced as a matched set, because they wear together.
Step 9 — Hand pack the bearings with fresh grease
Work fresh grease all the way into the bearing so it gets up between the rollers and the cage, not just smeared on the outside. The usual hand packing method is to put a glob of grease in your palm and press the wide end of the bearing into it over and over until grease pushes through from the other side. Work around the entire bearing until it is full, then lightly coat the outside.
Step 10 — Add grease to the hub interior
Apply a light coating of grease to the bearing races and inside the hub cavity. Do not overfill it, and if your trailer has brakes, be careful to keep grease off the brake components.
Step 11 — Reinstall the inner bearing and new seal
Place the packed inner bearing into the back side of the hub. Then install the new grease seal squarely and gently until it is fully seated. A seal driver is ideal, but a block of wood will protect the seal while you tap it into place.
Step 12 — Reinstall the hub onto the spindle
Carefully slide the hub back onto the spindle without damaging that new seal. With the hub in place, install the packed outer bearing, the washer and the spindle nut, in that order.
Step 13 — Adjust the bearing
This step is every bit as important as the grease.
- Tighten the spindle nut firmly while rotating the hub, to fully seat the bearing and spread the grease through the assembly
- Loosen the nut completely to release that pressure
- Retighten it by hand only, until it is just snug
- Back the nut off slightly to the nearest cotter pin hole, so the hub turns freely with no noticeable drag
Correct axle nut tension lets the hub turn smoothly without building heat or movement. Too tight and the bearings overheat and wear out early. Too loose and the movement can damage bearings, seals, hubs and the rest of the wheel end. Always follow your trailer manufacturer's adjustment and torque procedure when they give one.
Step 14 — Install the retainer and dust cap
Once the adjustment is correct, reinstall the cotter pin or retainer clip. Then reinstall the dust cap, tapping it in evenly until it is fully seated. That cap is what protects the bearing area from dirt and moisture.
Step 15 — Reinstall the wheel and torque the lug nuts
Put the wheel back on, snug the lug nuts, lower the trailer, and torque the lug nuts to the manufacturer's specification. Proper wheel torque is part of towing safely and it is not something to guess at — our trailer tire pressure and lug nut torque guide has the numbers and the re-torque schedule.
Step 16 — Spin and check your work
After reassembly, spin the wheel by hand. It should turn smoothly with no grinding and no wobble. Then check it for looseness:
- A small amount of movement at the tire is normal
- No movement at all can mean the bearings are too tight
- A lot of movement means they are too loose
After a short test tow, stop and carefully check the hub for unusual heat. Any noise, drag or play means you inspect the assembly again before you travel any further.
Common mistakes to avoid
- Reusing a grease seal — they are commonly damaged coming out
- Skipping the cleaning before inspection, because old grease hides wear and damage
- Packing fresh grease over contaminated grease instead of getting all the old grease out first
- Letting grease onto the brake components, because contamination affects braking
- Guessing at bearing adjustment or torque values instead of following the manufacturer's procedure
- Overtightening or undertightening the axle nut, which leads to overheating, excess movement and early bearing failure
Final takeaway
Bearing maintenance is not the cleanest job on the trailer, but it is one of the most valuable things you can do to prevent a breakdown. Clean components, a proper inspection, fresh grease, a new seal and a correct adjustment all work together to keep you rolling safely. If anything looks worn, damaged or questionable along the way, replace it or have the assembly inspected before you tow again.
Rather we did it?
Our service department repacks bearings and inspects the brakes, hubs and seals at both lots. Call and we will get you on the schedule.
Schedule your bearing service
Tell us the trailer and when works for you, and a Trailer Pro will get back to you to confirm the appointment. An axle service is repacking the bearings and inspecting the brakes, hubs and seals — if something needs replacing we will tell you before we do it.
Related guides
Source
This guide and the video on this page were built from “How to Manually Repack Trailer Wheel Bearings: A Step-by-Step Guide for Trailer Owners” by Savana Morrison, published June 4, 2026 by Trailer Safety Week, the safety campaign of the National Association of Trailer Manufacturers (NATM). The photographs in the video are the article's own.
The article notes that most manufacturers suggest repacking about once a year or every 12,000 miles. NC Trailers services at half that time interval — every 6 months or 12,000 miles, whichever comes first — so the interval on this page is ours, not the article's. Always follow your own trailer manufacturer's interval, grease type and torque specifications where they differ.