iBroPrat Aluminum Trailer Hub Caps 2pc 343-4009 with Oil-View Window & Gaskets

These are a pair of iBroPrat 343-4009 die-cast aluminum trailer hub caps with clear oil-view windows, two extra blue rubber plugs, and mounting gaskets for leak-resistant axle protection.

Built to match OEM sizing and fit common OEM part numbers (Stemco 343-4009, Spicer-Dana M10HK124, plus others), this two-piece set replaces worn or damaged wheel-end hub caps on trailers and light commercial axles. Each cap features a transparent inspection window so you can quickly check gear-oil level and condition, and the kit includes spare rubber plugs and gasketing to improve sealing during installation.

How will these hub caps simplify routine axle checks?

The integrated clear oil window lets you inspect lubricant level and color without removing the cap, saving time during pre-trip or maintenance checks. Markings on the window give a quick visual reference so you know when to add oil.

• See oil level through the high-strength plastic window
• Window markings for fast visual comparison
• No need to break the seal for basic inspections
• Includes spare plugs to maintain a tight seal after checks

Are these hub caps durable enough for heavy use?

Yes — the caps are die-cast from 380-series aluminum alloy and receive surface polishing for corrosion resistance and impact toughness. They are designed to resist cracking, warping, and environmental corrosion common on road-going trailers.

• 380 aluminum die-cast construction for strength
• Polished surface finish to reduce corrosion
• Designed to resist warping and cracking under load
• Waterproof seals and coated side plugs to prevent leaks

What mounting dimensions and vehicle compatibility should I check?

Confirm bolt-circle and flange diameters before ordering: these caps use a 5-1/2" bolt-hole spacing on center, a 4-3/8" flange inner diameter, and a 6-1/4" flange outer diameter. Model number 343-4009 fits many aftermarket and OEM applications listed for replacement.

• Bolt hole spacing: 5-1/2" on center
• Flange inner diameter: 4-3/8"
• Flange outer diameter: 6-1/4"
• Cross-references: Stemco 343-4009, Spicer/Dana M10HK124, and more

What’s included and how do I avoid leaks after installation?

The package contains two hub caps, mounting gaskets, two extra blue rubber side plugs, and sealant-coated side pipe plugs. Installation with the provided gaskets and seals reduces the chance of oil seepage around the oil window and mounting surface.

• Two die-cast aluminum hub caps with oil windows
• Mounting gaskets and dual gaskets at the oil window
• Two extra blue rubber plugs for replacement
• Side pipe plugs pre-coated with sealant to enhance sealing

Who this is for: fleet owners, trailer maintenance technicians, and DIYers who need a reliable, OEM-sized hub cap replacement that provides quick visual oil checks and strong sealing. If you replace Stemco 343-4009 or comparable hub caps, want clearer axle inspections, and need a cost-effective OEM-quality spare set, this iBroPrat two-piece kit is a practical match. For support or fitment questions, contact iBroPrat customer service for guidance and replacement options.