Trailer Axle Bearing Kit – #42 Spindle (1.75" × 1.25")
Part Number: BK3-100
Complete bearing service kit for one (1) trailer hub using a #42 spindle. Commonly used on 5,200 lb and 6,000 lb axles, and some 7,000 lb configurations. Includes inner and outer bearings, races, grease seal, cotter pin, and tang washer.
R&P Knowledge Hub
#42 spindles use a 1.75" inner journal and 1.25" outer journal. While the inner bearing (25580) is consistent, outer bearing and seal sizes can vary by hub manufacturer.
Always confirm bearing numbers stamped on existing components or verify race dimensions before ordering to ensure proper fitment.
Features
- Services one hub – order two kits per axle
- Fits standard #42 spindles (5.2K–6K typical applications)
- Compatible with EZ-Lube and standard grease systems
- Includes matched bearings, races, seal, and hardware
Specifications
| Specification | Detail |
| Outer Bearing | 15123 – 1.25" ID |
| Outer Race | 15245 – Matches 15123 |
| Inner Bearing | 25580 – 1.75" ID |
| Inner Race | 25520 – Matches 25580 |
| Grease Seal | 10-36 – 2.25" ID (verify if 2.125" required) |
| Spindle Type | #42 Spindle |
Verify bearing numbers and seal size before installation.
Included Components
| Quantity | Item |
| 1 | Inner Bearing (25580) |
| 1 | Outer Bearing (15123) |
| 2 | Bearing Races (25520 & 15245) |
| 1 | Grease Seal (10-36) |
| 1 | Cotter Pin |
| 1 | Tang / Lock Washer |
Shipping: Calculated at checkout.