Fortress Threaded Aluminum Oil Cap 5,200 lbs. - 8,000 lbs K21-303-00

Protect your trailer's oil bath hub system with the Fortress Threaded Aluminum Oil Cap, designed for compatible 5,200–8,000 lb trailer axles. Built for durability and a secure fit, this replacement oil cap helps keep your hub properly sealed, maintaining the correct oil level while preventing dirt, water, and road debris from reaching your wheel bearings.

A damaged, cracked, or leaking oil cap can allow lubricant to escape, leading to premature bearing wear and costly hub repairs. Replacing your oil cap is a simple, affordable way to protect your trailer's axle, extend bearing life, and ensure dependable performance every time you tow.

Features & Benefits

• Fits compatible Fortress oil bath hubs on 5,200–8,000 lb trailer axles
• Durable aluminum construction for long-lasting performance
• Threaded design provides a secure, reliable seal
• Helps prevent oil leaks and contamination
• Protects trailer hub bearings for smoother, safer towing
• Ideal for routine maintenance or replacing worn or damaged oil caps

Ideal Applications

Perfect for utility trailers, cargo trailers, equipment trailers, dump trailers, flatbed trailers, horse trailers, and RV trailers equipped with compatible Fortress oil bath hub systems.

Whether you're performing preventative maintenance or replacing a damaged cap after thousands of miles on the road, the Fortress Threaded Aluminum Oil Cap helps keep your trailer hubs properly lubricated and your bearings protected. Keep your trailer ready for every haul with a quality replacement part you can depend on.