4 Pack Billet Aluminum Oil Bath Caps 2-7/8"-12 — Replaces Dexter 21-35
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.
Overview
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.
R&P Service Insight
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.
- Durability: Billet aluminum helps replace commonly cracked or damaged plastic oil bath caps.
- Seal Support: Includes O-rings and rubber plugs for a complete cap refresh.
- Fitment Check: Confirm 2-7/8"-12 threads before installation.
R&P Knowledge Hub
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.
Brand & Fitment Note
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.
R&P Repair Insight
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.
- Thread Check: Confirm the hub accepts 2-7/8"-12 threaded caps before installation.
- Seal Check: Replace damaged O-rings or plugs to help prevent lubricant loss.
- Hub Check: Inspect for oil leaks, cracked caps, damaged threads, and contaminated lubricant.
Features
4-Pack Cap Kit
Includes four billet aluminum oil bath caps for servicing multiple hubs or completing a full trailer cap refresh.
Billet Aluminum Construction
Solid aluminum construction provides a stronger replacement option compared with common plastic oil bath caps.
Dexter 21-35 Replacement Reference
Designed to replace Dexter 21-35 style oil bath caps when the thread size and hub application match.
O-Rings & Plugs Included
Includes four O-rings and four rubber plugs for a cleaner, more complete installation.
Specifications
| 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 |
Fitment / Application
| 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. |
Included Components
| Quantity | Item |
|---|---|
| 4 | Billet aluminum oil bath caps |
| 4 | O-rings — reference 046-032-00 |
| 4 | Rubber plugs — reference 010-045-00 |
