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4 Pack Billet Aluminum Oil Bath Caps 2-7/8"-12 — Replaces Dexter 21-35 (21-35 Billet-Chrome-KitX4)

$193.84
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At a Glance

  • SKU: 21-35 Billet-Chrome-KitX4
PRODUCT INFORMATION

Product Details

Trailer Oil Bath Hub Caps

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.

Part Number: 21-35 Billet-Chrome-KitX4 4 Cap Kit 2-7/8"-12 Threads

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
Verify the 2-7/8"-12 thread size, hub style, cap seat, drum casting, O-ring condition, plug condition, and oil bath hub configuration before installation. Dexter references in this listing describe replacement-style compatibility only; this listing is for an aftermarket billet aluminum cap kit unless specifically stated otherwise.
Thank You For Choosing R&P Carriages As Your Online Shopping Source!
21-35 Billet-Chrome-KitX4 oil bath hub cap kit, 4 pack billet aluminum oil bath caps, 2-7/8-12 threaded oil bath cap, Dexter 21-35 replacement style oil cap, trailer oil bath hub caps, billet trailer hub oil caps, 8 lug oil bath hub cap, oil bath cap O-ring rubber plug kit, 046-032-00 O-ring reference, 010-045-00 rubber plug reference, 8-218 8-219 8-232 8-285 8-286 drum casting oil cap reference

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BEHIND THIS LISTING
PHOTOGRAPHY & RESEARCH Ariah Granados Ariah’s handwritten signature
DIGITAL PRESENTATION & DEVELOPMENT Ken Martin Ken’s handwritten signature
ONLINE SALES & QUALITY ASSURANCE Rayn Fisher
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