Trailer Bearing Size Chart & Identification Guide

This guide helps identify common trailer wheel bearings, races, and grease seals by axle capacity and spindle measurements.

Step 1: Identify Your Bearings

The most accurate way to identify trailer bearings is by:

-Removing the hub.

-Reading the bearing number stamped on the bearing cone.

-Measuring the spindle where each bearing rides.

Common Bearing Locations

-Inner Bearing = Closest to trailer frame

-Outer Bearing = Closest to wheel/tire

-Grease Seal = Installed behind inner bearing

Common Trailer Bearing Chart

Bearing Identification by Spindle Size

Measure the spindle with a caliper where each bearing rides.

Most Common Trailer Bearing Sets

#84 Spindle (3,500 lb Axles)

Inner Bearing: L68149
Outer Bearing: L44649
Seal: 10-19 Double Lip Seal

Common on:

-Utility trailers

-Boat trailers

-Landscape trailers

-Enclosed trailers

#42 Spindle (2,000 lb Axles)

Inner Bearing: L44643
Outer Bearing: L44643

Common on:

-Small utility trailers

-Jet ski trailers

-Lightweight boat trailers

5,200-6,000 lb Axles

Inner Bearing: 25580
Outer Bearing: LM67048

Common on:

-Equipment trailers

-Car haulers

-Heavy enclosed trailers

7,000 lb Axles

Inner Bearing: 25580
Outer Bearing: 14125A

Common on:

-Equipment trailers

-Dump trailers

-Gooseneck trailers

Seal Identification Chart

Quick Identification Cheat Sheet

If your outer bearing is L44649:

-Usually a 2,000-3,500 lb axle.

-Inner bearing typically L68149.

If your inner bearing is 25580:

-Usually a 5,200-7,000 lb axle.

-Check outer bearing to determine exact capacity.

If both bearings are L44643:

-Usually a 2,000 lb axle.

If outer bearing is 14125A:

-Usually a 7,000 lb axle.

Common Bearing Numbers Reference

Pro Tip

If the bearing numbers are unreadable, measure the spindle with a digital caliper to ±0.001". Matching spindle diameters is often the fastest way to identify the correct bearing, race, and seal kit for replacement.