Four - Billet Aluminum Oil Trailer Bath Caps 3.5"-12 Thread with Wrench
Four-piece billet aluminum oil bath cap kit with center plugs, O-rings, and matching billet wrench for compatible Dexter 9K–10K post-July 2009 axle applications using 3.5"-12 threaded hubs.
Key Measurements & Specs
| Specification | Detail |
|---|---|
| Part Number / SKU | 21-88-BILLET-WRENCH-KITX4 |
| Product Type | Oil bath hub cap kit |
| Thread Size | 3.5"-12 |
| Material | Billet aluminum |
| Application Reference | Dexter 9K–10K post-July 2009 axle applications |
| Quantity Included | 4 oil bath caps, 4 center plugs, 4 O-rings, and 1 billet wrench |
Fitment / Application
| Category | Details |
|---|---|
| Trailer System | Oil bath hub / axle lubrication system |
| Primary Fit | Dexter 9K–10K post-July 2009 axle applications using 3.5"-12 threaded hubs |
| Fitment Method | Match thread size, hub style, existing cap design, center plug, and O-ring requirements before ordering |
| Important Note | Verify axle model, hub thread size, and current oil cap dimensions before installation |
Top Features
| Feature | Buyer Benefit |
|---|---|
| Billet Aluminum Caps | Durable cap construction for compatible oil bath trailer hubs |
| 3.5"-12 Thread | Matches compatible threaded hub applications requiring this oil cap size |
| Four-Cap Kit | Supports servicing multiple hubs with one consistent kit |
| Wrench Included | Includes matching billet wrench for installation and removal of compatible caps |
Overview
This kit includes four billet aluminum oil bath caps for 3.5"-12 threaded hubs, plus four center plugs, four O-rings, and one billet wrench. It is intended for compatible Dexter 9K–10K post-July 2009 axle applications where the existing hub and cap measurements match.
R&P Service Insight
Oil bath caps help seal the hub and retain lubrication around the bearings. Correct cap sizing, thread engagement, plug condition, and O-ring sealing are all important for leak prevention and bearing protection.
- Measure First: Confirm the existing cap thread size before replacing oil bath caps.
- Inspect the Seal: Replace damaged or flattened O-rings during service to help prevent oil leaks.
- Check the Plug: Center plugs should seat securely and should not be reused if they are cracked, loose, or oil-soaked.
R&P Knowledge Hub
Compatibility: Designed for compatible 3.5"-12 threaded oil bath hub applications. Verify before ordering if your existing cap, hub, or axle information is unclear.
Vehicle / System Fit: Application reference is Dexter 9K–10K post-July 2009 axle applications using matching threaded oil bath hubs.
Installation Notes: Clean the hub threads, inspect the O-ring sealing area, and confirm the cap starts by hand before tightening.
Performance Insight: Oil bath hub systems depend on a properly sealed cap, plug, and O-ring to retain lubricant and protect bearing components.
Brand & Fitment Note
Selling Brand: R&P Carriages curated billet oil bath cap kit using the listed component part numbers.
Application Reference: Dexter axle references are used for compatibility guidance only.
What This Means: This listing is for a billet aluminum oil bath cap kit for compatible applications, not a guaranteed OEM-branded item unless specifically stated and verified.
Before Ordering: Verify axle rating, axle date/application, hub thread size, cap style, center plug style, O-ring requirement, and included components before installation.
R&P Repair Insight
When replacing oil bath caps, most fitment issues come from mismatched thread size, damaged hub threads, reused sealing components, or ordering by axle rating without confirming the actual hub cap size.
- Thread Check: Confirm the cap is 3.5"-12 before ordering.
- Hub Condition: Inspect hub threads for cross-threading, burrs, or damage before installing the new cap.
- Leak Check: After installation, verify that the O-ring and center plug are seated correctly before returning the trailer to service.
Features
Solid Billet Aluminum Construction
Billet aluminum oil bath caps for compatible trailer hub applications requiring 3.5"-12 threaded caps.
3.5"-12 Thread Specification
Designed for hubs that use the 3.5"-12 oil bath cap thread size.
Dexter 9K–10K Application Reference
Listed for compatible Dexter 9K–10K post-July 2009 axle applications where measurements match.
Installation Wrench Included
Includes one billet wrench listed as Billet-Wrench-2.5 for compatible 2.5" hex cap installation and removal.
Included Components
| Part Number | Quantity | Item |
|---|---|---|
| 21-88 | 4 | Billet aluminum oil bath cap, 3.5"-12 thread |
| 046-032-00 | 4 | Center plug |
| 010-050-00 | 4 | O-ring |
| Billet-Wrench-2.5 | 1 | Billet aluminum wrench for compatible 2.5" hex caps |
