Knott Dust Cap - 4 Pack

Internal fit means the hub cap slots *into* the hub's center opening, rather than fitting *over* the outside of the hub. It requires a specific internal diameter measurement of the hub.

You need to measure the internal diameter of the hub where the cap will sit. Use a tape measure or calipers to get an accurate reading. For these caps, the measurement must be 64mm.

They are suitable for trailers with Knott hubs that have a 64mm internal diameter. Always confirm your hub's specifications before purchasing.

The primary purpose of a dust cap is to prevent dirt, dust, grit, and moisture from entering the wheel hub and contaminating the wheel bearings, which can lead to premature wear and failure.

This listing is for a pack of four (4) genuine Knott metal trailer hub caps.

They are made of steel for strength and durability, and are zinc plated for corrosion resistance.

While technically possible, painting may affect the zinc plating and could chip over time. Ensure the surface is properly prepared and use a paint suitable for metal if you choose to paint them.

Ensure the hub opening is clean and free of debris. Apply gentle, even pressure. If resistance is significant, double-check that the hub diameter is indeed 64mm and that you are not trying to fit an external cap to an internal recess.

The hub diameter may be slightly larger than 64mm, or the internal seating surface is damaged. Ensure the cap is fully seated. For a slightly loose fit, a thin bead of suitable sealant around the edge before tapping into place might help, but verify compatibility with bearing grease.

While zinc plating offers protection, prolonged exposure to harsh conditions can lead to surface rust. Clean the affected area and consider applying a metal protectant suitable for automotive use. Check for physical damage that may have compromised the plating.