SyunsXoon Vortex Replacement Hub Caps — 2-Pack 2 5/16 in Thread, O-ring Seal

If your trailer’s Vortex-style hub cover is lost, cracked, or leaking grease, these SyunsXoon caps restore a secure threaded seal. They match the 2 5/16" outer thread diameter used on many Dexter marine and standard hubs and are intended for Vortex hubs with five bolts (not for six-lug hubs). Constructed from durable hard plastic and supplied with O-ring sealing, this two-pack gives a dependable, easy-to-install replacement without the cost of a full hub kit.

How do these caps fit my Dexter Vortex hub?

Each cap follows the Vortex 81143 / 48355v thread dimensions and seating form, designed to screw into Vortex-style hub assemblies that accept a 2 5/16" outer thread diameter. They are specifically for hubs using five bolts; they will not fit six-lug configurations.

• Compatible references: 81143, 48355v, K71-G01-73, 21-261.
• Outer thread diameter: 2 5/16" to match Vortex hub specifications.
• Intended for Dexter marine and standard 1250–1750 lb hub applications.
• Not suitable for six-lug hubs or non-threaded hub covers.

What materials and sealing features do these replacement caps use?

SyunsXoon caps are molded from a high-strength hard plastic formulated to resist cracking and deformation from handling and road vibration. Each cap includes an O-ring that compresses when threaded in, forming a grease-resistant barrier to help keep bearings lubricated and contaminants out.

• Durable hard plastic construction for impact and wear resistance.
• O-ring seal reduces grease leakage and keeps out dirt and water.
• Threaded body allows repeatable installation and removal without press fittings.
• Sold as a two-pack for spare or dual-axle replacement needs.

How simple is installation and maintenance?

Installation is straightforward: align the cap threads with the hub, hand-start the threads, then tighten until the O-ring seats securely. Removal is just as easy—unscrew the cap to access the spindle nut and bearings for inspection, lubrication, or service.

• Threaded design requires only basic hand tools or a cap wrench for tightening.
• O-ring replacement is quick if it wears over time; caps can be reused.
• Ideal for routine trailer maintenance schedules and seasonal checks.
• Keeps bearing grease contained between service intervals.

Will these caps match original Dexter appearance and performance?

While aftermarket, these caps replicate the critical fit dimensions of Dexter Vortex caps to provide a secure mechanical fit and functional sealing. The finish and exact cosmetic details may vary slightly, but function and compatibility with specified hub models are the priority.

• Designed to meet the same thread and sealing profile as OEM Vortex caps.
• Functionally equivalent for keeping grease in and contaminants out.
• Economical two-pack lets you replace one now and keep a spare on hand.
• Customer support available for fitment questions and response within 24 hours.

Who is this for: trailer owners, boaters, and fleet managers who use Dexter Vortex-style hubs (1250–1750 lb) with five-bolt patterns and need a reliable, easy-to-install replacement hub cap. This two-pack is useful for single-axle repairs, quick spares for multi-axle trailers, or anyone maintaining bearings and seals without replacing full hub assemblies. If you’re unsure about fit, check your hub’s outer thread diameter (2 5/16") and bolt count before ordering.