Match the part number, measurements and connection points that apply to your trailer.
| Part Number | Match the number stamped on the original bearing or seal. |
|---|---|
| Dimensions | Measure the mating surfaces when a number is unavailable. |
| Hub / Axle | Use capacity as context, not as the only fitment check. |
Heavy-duty aftermarket billet aluminum replacement oil bath cap kit for trailer hubs using 2-7/8"-12 threaded caps. Includes four caps, four O-rings, and four rubber plugs.
This aftermarket billet aluminum oil bath cap kit is designed as a durable replacement for common plastic oil caps used on compatible trailer oil bath hubs. The caps are built for hubs using 2-7/8"-12 threaded oil bath caps and are commonly used with many 8-lug oil bath hub and drum applications. Fitment should always be confirmed by thread size, hub type, and casting number before ordering.
Oil bath caps are a small part with a big job. A failed or damaged cap can lead to lubricant loss, bearing damage, and trailer downtime.
Compatibility: Designed for hubs using 2-7/8"-12 threaded oil bath caps and commonly referenced as a replacement for Dexter 21-35 style caps.
Vehicle / System Fit: Commonly used on many 8-lug oil bath trailer hub and drum setups, including select disc brake applications.
Installation Notes: Inspect the hub threads, remove old gasket material or debris, lubricate the O-ring as needed, and install carefully to avoid cross-threading.
Performance Insight: Oil bath caps help seal hub lubricant while allowing visual inspection and maintenance of oil level. A damaged cap can allow oil loss and expose bearings to failure risk.
Selling Brand: Aftermarket replacement billet aluminum cap kit.
Application Reference: Replaces Dexter 21-35 style oil bath caps when the hub uses matching 2-7/8"-12 threads.
What This Means: This listing includes four aftermarket billet aluminum caps with matching O-rings and rubber plugs.
Before Ordering: Verify thread size, hub style, drum casting number, and existing cap type. Do not order by axle weight alone.
When replacing oil bath caps, inspect the surrounding hub area and lubricant condition at the same time. A cap replacement is also a good time to check for contaminated oil, damaged threads, worn plugs, or signs of leaking around the cap seat.
Includes four billet aluminum oil bath caps for servicing multiple hubs or completing a full trailer cap refresh.
Solid aluminum construction provides a stronger replacement option compared with common plastic oil bath caps.
Designed to replace Dexter 21-35 style oil bath caps when the thread size and hub application match.
Includes four O-rings and four rubber plugs for a cleaner, more complete installation.
| Specification | Detail |
|---|---|
| Part Number | 21-35 Billet-Chrome-KitX4 |
| Listing SKU | 21-35 Billet-Chrome-KitX4 |
| Brand | Aftermarket Replacement |
| Product Type | Oil Bath Hub Cap Kit |
| Quantity Included | 4 Caps, 4 O-Rings, 4 Rubber Plugs |
| Application | Trailer oil bath hubs using matching 2-7/8"-12 threaded caps |
| Material / Finish | Billet Aluminum / Chrome-Style Polished Appearance |
| Key Measurement | 2-7/8"-12 Thread Specification |
| Replacement Reference | Dexter 21-35 style oil bath cap |
| Common Drum Castings | 8-218, 8-219, 8-232, 8-285, 8-286 |
| Category | Details |
|---|---|
| Vehicle / System | Trailer oil bath hub systems |
| Primary Fit | Hubs requiring 2-7/8"-12 threaded oil bath caps |
| Secondary Fit | Commonly used with many 8-lug oil bath drums and select disc brake setups |
| Notes | Verify thread size, hub type, drum casting, existing cap style, and sealing components before ordering. |
| Quantity | Item |
|---|---|
| 4 | Billet aluminum oil bath caps |
| 4 | O-rings — reference 046-032-00 |
| 4 | Rubber plugs — reference 010-045-00 |
Selected from R&P customer feedback for Bearing / Seal products and related trailer service.
“I've ordered lots of trailer repair parts from them, always fast service, well packed, and the right parts. I highly recommend.”
“Would like to say thanks to everyone at R and P Carriages parts were delivered fast and with the very helpful staff, the right parts were sent the first time. Thanks Happy Holiday's.”
“Received swivel d-ring tie down 4 days after my wife ordered them , great price and came with backing plates. I received exactly what I paid for, thanks for the great service. Chris Davis , Mooresville NC”
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