Match the part number, measurements and connection points that apply to your trailer.
| Hub Face | Measure hub face to hub face. |
|---|---|
| Spring Center | Measure mounting centers and confirm perch configuration. |
| Capacity | Match the required axle rating. |
| Brakes | Confirm brake type and flange configuration. |
Part Number: K21-304-00
Genuine Dexter FORTRESS series aluminum oil bath hub cap designed for use on heavy-duty oil-lubricated trailer hubs. This cap features a 3.75" diameter and is intended for select 10,000 lb through 16,000 lb axle applications. Engineered by Dexter for compatibility with specific hub and spindle systems.
| Specification | Detail |
|---|---|
| Manufacturer | Dexter |
| Series | FORTRESS |
| Part Number | K21-304-00 |
| Hub Type | Oil bath |
| Cap Diameter | 3.75" |
| Axle Rating Range | Typically used on 10K–16K axle systems |
| Material | Aluminum |
This cap replaces several legacy oil cap designs used across multiple axle platforms. Verify hub bore size, spindle nut clearance, and manufacturer specifications before installation.
