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. |
Genuine Dexter FORTRESS 2.875" diameter aluminum oil caps designed for 5,200–8,000 lb trailer axle applications. Built for durability and precise fit, these caps are engineered to meet the performance demands of commercial and heavy-duty trailer use.
Designed to fit select Dexter, Rockwell, Lippert, and AL-KO axle configurations. Always verify hub bore diameter before installation.
| Component | Quantity |
|---|---|
| Dexter FORTRESS 2.875" Aluminum Oil Caps (replaces 21-35) | 2 |
| Specification | Detail |
|---|---|
| Cap Diameter | 2.875" |
| Material | Aluminum |
| Axle Compatibility | 5,200–8,000 lb |
| Manufacturer | Dexter |
| Individual Part Number | K21-303-00 |
| Brand | Part Numbers |
|---|---|
| Dexter | K71-038-00, 021-035-00, 21-35, K21-297-00, 021-8001 |
| Valcrum | ST-2875 |
| Rockwell | 8001 |
| Lippert | 695815 |
Important: Verify hub bore diameter and axle compatibility before installation.
Selected from R&P customer feedback for Trailer Axle / Running Gear products and related trailer service.
“Got me the axle I needed right away with custom spring perch setting.”
“Had a trailer made to my needs.ken was able to get it done and at a price that was very acceptable.i have bought parts there for 2 other trailers and always in stock”
“Quality work. Staff is polite. Great job welding a project for me. Didn't even want to charge me, so I bought them a case of Corona. They were ecstatic. I ever need a welding or like that R&P Carriages is #1 !!!!!”
Need help matching a part? Send us photos, part numbers and measurements. We can help narrow it down before you order.
