Two - Billet Aluminum Trailer Oil Bath Caps 3.5"-12 Thread with Wrench
Two billet aluminum oil bath caps with matching service wrench for compatible 3.5"-12 threaded oil bath hub applications. Commonly used on Dexter 9K–10K post-July 2009 axle applications where the existing cap, hub, and thread size match.
Key Measurements & Specs
| Specification | Detail |
|---|---|
| Part Number / SKU | 21-88-BILLET-WRENCH-KITX2 |
| Selling Brand | R&P Carriages curated service kit |
| Product Type | Billet aluminum oil bath cap kit |
| Thread Specification | 3.5"-12 threaded oil cap application |
| Material | Billet aluminum caps |
| Quantity Included | 2 oil bath caps, 2 center plugs, 2 O-rings, and 1 billet wrench |
Fitment / Application
| Category | Details |
|---|---|
| Trailer / System | Oil bath trailer hub applications |
| Primary Application | Compatible with Dexter 9K–10K post-July 2009 applications where the 3.5"-12 oil cap fitment matches |
| Fitment Method | Verify existing oil cap number, thread diameter, thread pitch, hub style, and sealing components before ordering |
| Important Note | Application reference only. This listing is not claiming a Dexter OEM-branded part unless specifically verified on the product packaging. |
Top Features
| Feature | Buyer Benefit |
|---|---|
| Billet Aluminum Caps | Durable cap construction for oil bath hub service and replacement |
| 3.5"-12 Thread Fit | Matches compatible threaded oil bath hub applications using this thread specification |
| Pair Kit | Includes two caps for servicing both sides of a compatible axle setup |
| Wrench Included | Includes matching billet wrench for cap installation and removal |
Overview
This R&P Carriages curated kit includes two billet aluminum 21-88 style oil bath caps, two center plugs, two O-rings, and one billet wrench. It is intended for compatible 3.5"-12 threaded oil bath hub applications, including listed Dexter 9K–10K post-July 2009 axle applications where the buyer verifies the existing cap, hub, and thread specifications before installation.
R&P Service Insight
Oil bath caps are small parts, but they are critical to hub lubrication. A correct cap must match the hub thread, seal properly, and retain lubrication without cross-threading or damaging the O-ring during installation.
- Check the old cap: Confirm the existing cap number, thread size, and hub style before ordering.
- Inspect the sealing surface: Clean the hub threads and sealing area before installing the replacement cap and O-ring.
- Use the correct tool: The included wrench helps install and remove the cap without relying on improvised tools.
R&P Knowledge Hub
Compatibility: Designed for compatible 3.5"-12 threaded oil bath hub applications. Verify before ordering if your axle, hub, or cap has been changed from the original configuration.
Vehicle / System Fit: Commonly used with listed Dexter 9K–10K post-July 2009 oil bath hub applications where measurements match.
Installation Notes: Replace the O-ring and center plug during cap service when included. Do not force the cap if threads do not start cleanly.
Performance Insight: The oil cap helps retain hub lubricant and protect the bearing assembly. Proper fit and sealing are essential for oil bath hub reliability.
Brand & Fitment Note
Selling Brand: R&P Carriages curated service kit
Application Reference: Dexter references are used for compatibility and application identification only.
What This Means: This listing is for a billet aluminum oil bath cap kit for compatible applications, not a guaranteed Dexter OEM-branded item unless specifically stated and verified.
Before Ordering: Verify the existing cap number, thread size, hub type, axle rating, oil bath setup, O-ring fit, and included components before installation.
R&P Repair Insight
When replacing oil bath caps, fitment problems usually come from mismatched thread size, damaged hub threads, missing sealing components, or assuming all high-capacity Dexter-style oil bath caps are the same.
- Thread Check: Confirm the 3.5"-12 threaded cap specification before ordering.
- Seal Check: Make sure the O-ring seats correctly and the center plug is fully installed.
- Hub Check: If the hub threads are damaged or contaminated, correct that issue before installing the new cap.
Features
Billet Aluminum Construction
Solid billet aluminum cap design for compatible oil bath hub service and replacement.
3.5"-12 Thread Specification
Built for compatible threaded oil bath hub applications using the 3.5"-12 cap size.
Two-Cap Service Kit
Includes two oil bath caps so both sides of a compatible axle setup can be serviced together.
Wrench Included
Comes with one matching billet wrench for installation and removal of compatible 2.5" hex caps.
Included Components
| Part Number | Quantity | Item |
|---|---|---|
| 21-88 | 2 | Billet aluminum oil bath cap, 3.5"-12 thread |
| 046-032-00 | 2 | Center plug |
| 010-050-00 | 2 | O-ring |
| Billet-Wrench-2.5 | 1 | Billet aluminum wrench for 2.5" hex caps |
