At a Glance

> Wear Resistance: Aluminum construction prevents the cracking and warping common in polycarbonate caps.
> Chemical Guard: UV-resistant sight glass and alloy body withstand road chemicals and sun exposure.
> Easy Access: Integrated fill and drain ports simplify lubricant changes without hub disassembly.
> Thread Check: Verify your hub thread diameter is 2-7/8" to match these specific ALKO/Hayes style hubs.
> Tooling: Avoid using standard pipe wrenches, as they can damage the machined finish and void the manufacturer warranty.
Brand: Need a Trailer Part
SKU: D021-212-10

Before You Order

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.

Product Details

Hub & Wheel End Maintenance

Threaded Aluminum Oil Cap Kit for ALKO and Hayes 7K - 8K Axles, 2-7/8"

Heavy-duty aluminum alloy protection with visual monitoring and magnetic debris filtration for professional-grade hub performance.

Part Number: D021-212-10 Fits 7,000lb - 8,000lb Axles

Overview

Upgrade your trailer's wheel end protection with this Heavy Duty Aluminum Alloy Lube Cap. Engineered for versatility, this cap is designed to perform in both grease and oil bath applications. Featuring a clear indicating window for instant lubricant level checks and a magnetic vent plug to trap debris, it is the ultimate professional-grade solution for preventing hub failure and extending bearing life.

R&P Service Insight

This component is the ideal upgrade from standard plastic caps, offering significantly higher resistance to environmental stress and load impact.

Wear Resistance: Aluminum construction prevents the cracking and warping common in polycarbonate caps.
Chemical Guard: UV-resistant sight glass and alloy body withstand road chemicals and sun exposure.
Easy Access: Integrated fill and drain ports simplify lubricant changes without hub disassembly.

R&P Knowledge Hub

Compatibility: Standard 1/8"-27 NPTF plug threading; fits most heavy-duty trailer hubs designed for screw-in oil or grease caps.

Vehicle / System Fit: Ideal for Utility, Flatbed, and Equipment trailers using grease or oil bath hub systems.

Installation Notes: To safeguard the Valcrum Warranty, ensure that the Valcrum Oil Cap Wrench is used for installation and removal. Do not over-torque.

Performance Insight: The aluminum alloy body dissipates heat more effectively than plastic, while the integrated magnet pulls metallic wear particles out of suspension to clean the lubricant actively.

R&P Repair Insight

Before proceeding with your order or installation, please perform these essential checks to ensure a perfect fit and long-term reliability.

Thread Check: Verify your hub thread diameter is 2-7/8" to match these specific ALKO/Hayes style hubs.
Tooling: Avoid using standard pipe wrenches, as they can damage the machined finish and void the manufacturer warranty.
O-Ring Seat: Ensure the hub face is clean and free of debris to allow the new O-ring to create a pressure-tight seal.

Features

Dual-Purpose Design

Fully compatible with both Grease and Oil Bath lubrication systems for maximum versatility.

Visual Monitoring

Integrated indicating window allows for rapid "at-a-glance" lubricant level and clarity checks.

Magnetic Protection

The included magnetic vent plug removes harmful metallic micro-particles from your hub's lubricant.

Heavy Duty Build

Machined aluminum alloy body provides superior impact resistance and durability over OEM plastic units.

Specifications

Specification	Detail
Part Number	D021-212-10
Product Type	Heavy Duty Hub Lube Cap
Application	Grease or Oil Bath Hubs
Material / Finish	Aluminum Alloy / Machined
Key Measurement	2-7/8" Diameter
Port Thread	1/8"-27 NPTF

Fitment / Application

Category	Details
Vehicle / System	Utility, Equipment, and Heavy Duty Trailers
Primary Fit	ALKO and Hayes Axles
Axle Capacity	Standard 7k, 8k, and Heavy Duty Axles
Notes	Requires Valcrum Wrench for warranty compliance. One kit per wheel.

Included Components

Quantity	Item
1	Aluminum Alloy Lube Cap Body
1	Magnetic Vent Plug
1	Sealing O-Ring/Gasket Set
1	1/8"-27 NPTF Plug & Hardware

Verification: Please verify your hub thread diameter and lubricant type before ordering. Using improper tools may damage the finish and void the manufacturer warranty.

View More Valcrum Hub Options

Valcrum VAL-ALCAP-HD, aluminum oil bath cap, trailer grease cap, magnetic hub plug, trailer axle maintenance, 1/8 NPTF hub cap, oil bath sight glass, heavy duty trailer parts, ALKO 7k oil cap, Hayes 8k oil cap.

Threaded Aluminum Oil Cap Kit for ALKO and Hayes 7K - 8K Axles, 2-7/8" (D021-212-10)