YUANTUO Trailer Axle Oil Bath Dust Caps K71-704-00 — Clear Polycarbonate 4‑Pack, 3.5" OD 12‑Thread for Dexter 9K/10K

YUANTUO K71-704-00 21-88 oil bath dust caps are transparent polycarbonate axle seals designed to fit Dexter 9K/10K trailer drums (3.5" OD, 12-thread) and come as a 4-piece maintenance kit.

This replacement kit provides the complete set of dust caps and seals needed to protect wheel-end components on compatible trailer axles. The caps are clear and colorless, finished from durable polycarbonate, and packaged with rubber plugs and O-rings for straightforward installation. Before ordering, verify fitment: these caps are made for Drum No. 8-415 (from July 2009) and Drum No. 8-430 (from April 2013) and match the OE part K71-704-00 specifications.

How do these dust caps protect my trailer axle?

The caps form a barrier that keeps grease and oil inside the axle hub while blocking dirt, water and road debris from entering. Maintaining the lubricant inside the assembly helps bearings and seals work under less stress and reduces wear on moving parts. Using fresh, properly fitting dust caps preserves drivability and minimizes the need for premature repairs.

• Seals grease reservoirs to reduce lubricant loss and contamination.
• Prevents dirt and moisture ingress that can accelerate corrosion.
• Includes O-rings and rubber plugs to ensure a complete seal.
• Clear design allows quick visual inspection of lubricant level.

Will these caps fit my trailer hubs and how do I confirm compatibility?

These caps are manufactured to match the K71-704-00 OE dimensions: 3.5" thread outer diameter with 12 threads. They are specified to fit Dexter drums 8-415 produced after July 2009 and 8-430 produced after April 2013. Measure your drum's thread size and compare drum numbers or owner's manual to confirm a match before installing.

• 3.5" thread OD and 12-thread pitch to match OE sizing.
• Explicitly listed for Drum No. 8-415 (post-July 2009) and 8-430 (post-April 2013).
• Check your drum casting number or service manual for verification.
• Contact a technician if you are unsure about hub compatibility.

What comes in the package and is installation difficult?

The kit includes everything needed to replace four axle dust caps: four polycarbonate caps, four rubber plugs and four O-rings. Installation is typically a direct swap — remove the old cap, clean seating surfaces, place the O-ring and rubber plug, and thread the new cap into place until seated. No special tools are required beyond common hand tools to remove the existing cap.

• 4x YUANTUO 21-88 oil bath dust caps (K71-704-00 size).
• 4x rubber plugs (46-32) to block lubrication ports when needed.
• 4x O-rings (10-163) to complete the sealing surface.
• Designed for straightforward, on-vehicle replacement.

How often should I replace these dust caps and what signs indicate replacement?

Replace dust caps when sealing efficiency drops, when visible damage appears, or when scheduled maintenance calls for renewal. Look for cracking, deformation, deep scratches or grease leakage around the cap base; these are clear signals that the cap is no longer protecting the hub effectively. Routine replacement as part of axle maintenance helps extend the life of wheel bearings and other components.

• Replace if the cap is cracked, warped, or scratched deeply.
• Swap during hub servicing or if oil/grease loss is observed.
• Regular replacement prevents contamination and component wear.
• Use original-fit caps to maintain correct sealing dimensions.

Who is this for: This YUANTUO kit is intended for trailer owners, fleet managers and repair shops working on Dexter 9K/10K axles that match the listed drum numbers and dimensions. It suits anyone seeking a complete, OE-sized replacement set — four transparent dust caps with matching plugs and O-rings — to restore proper axle lubrication and protection during routine maintenance or axle rebuilds. Always confirm drum number and thread measurements before purchasing to ensure proper fitment.