Axle capacity
Find the axle tag or the trailer manufacturer’s specification. A 7K kit is for compatible 7K axle applications, not every tandem axle trailer or every heavy-duty-looking hub.
Trailer hub service
Trailer Bearing Kits for 7K Axles
Replace worn hub service parts with a bearing kit that matches the axle, hub, bearing numbers, and seal on your trailer. Northline can help you start with the details that matter before you order.
Start at the hub
Match the service parts, not just the trailer.
Trailer bearings let the hub and wheel turn around the spindle. They work with the races, grease, seal, washer, nut, and cotter pin as one serviceable assembly. When a bearing is worn, contaminated, loose, noisy, or damaged, the repair needs to match the actual hub and axle parts, not a rough guess based on trailer length or what a similar trailer uses.
A trailer bearing kit can simplify a planned service because it gathers several related replacement parts in one place. It is still important to confirm that every included piece is right for the trailer. The axle capacity, hub or brake drum, inner and outer bearing markings, seal dimensions, and spindle condition all matter. A kit that is close but not correct can create a poor fit, a leaking seal, or an unreliable bearing adjustment.
Northline's current 7K axle bearing kit includes an inner bearing, outer bearing, axle seal, castle nut, and cotter pin. Use that list as a starting point, then compare the old parts and the trailer's axle information before buying. If the part numbers are hard to read, a photo of the removed bearing, seal, hub, and axle tag can make it much easier to narrow down the right next step.
Confirm the fit first
Four checks before you choose a bearing kit.
Bearing numbers
Clean the old inner and outer bearings and read the stamped numbers when possible. Those numbers are more dependable than comparing the bearing by eye or relying on the trailer’s overall size.
Seal dimensions
Match the seal to the hub bore and spindle surface. A seal needs the right inside and outside dimensions to retain grease and keep water, dust, and road grit out of the hub.
Hub and spindle condition
Inspect the races, hub bore, spindle, threads, and sealing surface. A kit cannot correct a scored spindle, damaged race seat, cracked hub, or brake problem that needs separate attention.
When bearings need attention
Do not let a small hub warning turn into a roadside failure.
Routine inspection is the best time to catch a bearing service need. Look for grease around the inside of the wheel or brake components, a loose wheel, roughness while turning the hub, discoloration from heat, damaged dust caps, or a seal that is no longer doing its job. After towing, compare hub temperature carefully without touching a hot surface. One hub that is noticeably hotter than the others deserves a closer look before the next trip.
Water and contamination can shorten bearing life quickly. Boat launches, wet roads, long storage periods, damaged caps, and a failed seal can allow moisture or grit into the hub. Grease that looks milky, dirty, burnt, or full of metal particles is not a sign to add more grease and hope for the best. It is a reason to clean, inspect, and replace parts as needed using the trailer and component manufacturer’s guidance.
During service, keep every part organized by hub. The inner bearing and seal sit on the back side of the hub, while the outer bearing, washer, nut, and cotter pin secure the front. The bearing races must be in good condition and properly seated. Packing a new bearing with the right grease and setting the adjustment correctly are just as important as choosing the part number. Over-tightening can create heat, while a loose adjustment can allow unwanted movement and damage.
If the trailer has electric brakes, inspect the brake drum and backing plate while the hub is off. A leaking seal can contaminate brake shoes, and a problem in the brake area can be easy to miss once the hub is back in place. Northline's trailer brake assembly page can help you understand the related brake components before you reassemble the wheel end.
See Trailer Brake Assemblies ›A better hub-service routine
Protect the new kit after the repair.
Use a clean work area
Keep dirt, rags, and loose hardware away from the bearing surfaces. Small contaminants can shorten the life of a new bearing before the trailer even leaves the driveway.
Inspect the races
Look for pitting, scoring, bluing, cracks, or a race that no longer sits securely in the hub. Bearings and races work as a pair, so a damaged race needs attention before installing a new bearing.
Set the seal carefully
Install the compatible seal squarely and protect its sealing lip during assembly. A bent, torn, or wrong-size seal can let grease reach the brakes or allow contamination into the hub.
Recheck after service
Follow the trailer manufacturer's directions for bearing adjustment, wheel torque, and service intervals. Before a full load or long trip, make a short test run and inspect the hub again.
Never work beneath a trailer supported only by a jack. Park on level, firm ground, chock the opposite wheels, and use properly rated equipment and support stands whenever wheel-end service requires the trailer to be raised.
Shop Trailer Bearing Kits
View Axles & Bearings ›Northline's current selection includes a 7K axle bearing kit. Confirm the axle, hub, bearing, and seal details against your trailer before adding it to your cart.
Trailer bearing kit
7K Trailer Axle Bearing Kit
This kit includes one inner bearing, one outer bearing, one axle seal, one castle nut, and one cotter pin for a compatible 7K axle application.
$29.08View Bearing Kit ›Need a second look?
Bring the old parts and we will help narrow it down.
Call Northline with the axle capacity, bearing numbers, and a clear photo of the old seal, hub, and spindle. Those details give the conversation a useful starting point before you order a replacement kit.
Frequently asked questions
Trailer bearing kit questions.
What comes in a trailer bearing kit?
A bearing kit groups the service parts needed for one compatible hub. Northline's 7K kit includes an inner bearing, outer bearing, axle seal, castle nut, and cotter pin. Always compare the included parts with the trailer in front of you before ordering.
How do I know if a bearing kit fits my trailer?
Start with the axle capacity and hub or drum information, then verify the inner and outer bearing numbers and seal dimensions from the parts being replaced. Trailer size alone is not enough to confirm a bearing kit.
Should I replace both sides of the axle?
Inspect both hubs. If the bearings, seals, grease condition, or mileage are similar on each side, servicing both sides together can make sense. Replace only what the trailer's condition and the manufacturer's service guidance support.
Can I keep towing with a noisy or hot trailer hub?
A noisy, loose, leaking, or unusually hot hub needs attention before the next trip. Stop in a safe place, let the equipment cool, and inspect the cause rather than trying to finish the haul with a damaged bearing or seal.