Fulton 001501 · 1.786 in grease cap
Zinc-plated steel cap for the nominal 1.786-in hub opening. Its manufacturer-distributed detail lists a 0.63-in crown and 0.27-in flange.
View this MPN and item conditionFulton Trailer Hub Grease Caps: Diameter & Depth Guide
A missing or dented trailer wheel grease cap should be replaced with the right press-fit diameter and cap depth. Fulton sells several metal bearing dust caps that look alike in a catalog photo but differ at the hub opening. Use the exact stamped MPN, when available, or carefully measure the hub before buying a replacement.
Metal grease cap versus bearing-protector cover
Press-fit metal grease capA closed steel cap seats directly into the trailer hub opening and helps keep dust, spray and road debris away from the bearing cavity. Fulton 001501, 001505, 001520, 001604 and 001609 belong to this group. They do not have a grease fitting.
Vinyl bearing-protector coverFulton BB19800112 is a two-pack of flexible protective caps intended to fit over a compatible 1.98-in bearing-protector assembly. It is not a replacement metal hub grease cap or a complete bearing protector.
Fulton metal dust-cap diameter chart
These are the nominal hub/cap fit dimensions listed for each part number. Always compare with an accurate measurement of your actual hub bore, including whether the new part can seat fully.
| Fulton MPN | Listed nominal fit diameter | Reported cap height | Part type |
|---|---|---|---|
| 001501 | 1.786 in | 0.89 in overall | Metal drive-in grease cap; one per listing |
| 001505 | 1.988 in | Check actual cap depth | Metal drive-in grease cap; one per listing |
| 001520 | 2.446 in | 1-5/16 in tall | Metal drive-in grease cap; one per listing |
| 001604 | 2.446 in | 1.16 in overall | Metal drive-in grease cap; one per listing |
| 001609 | 3.125 in | Check hub clearance | Metal drive-in grease cap; one per listing |
Two 2.446-inch cap models: 001520 and 001604 share the same nominal seating size, but their published heights are different: approximately 1-5/16 in for 001520 and 1.16 in for 001604. Check the hub's available depth and the cap profile rather than assuming either is identical.
Measure the hub before selecting a grease cap
- Remove the old cap carefully: If the damaged cap is available, note any stamped reference and inspect the seating flange.
- Measure the opening: Use a caliper at the clean hub bore where the cap presses in. Do not estimate its size from trailer tire diameter or bolt count.
- Check depth: Compare how far the existing cap protrudes with available clearance around spindle, cotter pin and trailer wheel hardware.
- Identify the product type: A vinyl cover for a greaseable bearing protector is not a metal drive-in hub cup.
- Inspect the bearing system: If a cap has been missing for some time, check for contaminated grease, corrosion or damaged bearings and seals before returning the trailer to service.
Common questions about Fulton hub caps
Can I use 001604 instead of 001520? Not based only on their 2.446-in diameter. Compare the required clearance, cap crown depth and exact hub specification before substituting.
Does 001505 fit every 1.98-in bearing protector? No. 001505 is a metal press-fit grease cap for a hub opening. A bearing-protector cover has a different attachment method.
Does BB19800112 include the metal bearing protector? The manufacturer lists it as two replacement vinyl protective covers. It is not the complete bearing-protector assembly.
Compare the exact Fulton product listings
Check each listing for its actual condition, supplied quantity and current availability. Catalog photographs show the product type, not necessarily the condition of the individual item offered.
Fulton 001505 · 1.988 in grease cap
Zinc-plated steel cap for a nominal 1.988-in hub opening. Do not confuse this press-fit metal cup with a 1.98-in bearing-protector cover.
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Fulton 001520 · 2.446 in grease cap
Zinc-plated, drive-in steel cap. One of two Fulton MPNs in this guide with the same nominal 2.446-in seating diameter; compare depth.
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Fulton 001604 · 2.446 in grease cap
Steel grease cap with a 0.88-in crown and 0.28-in flange listed by a parts distributor. Not identical in overall depth to 001520.
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Fulton 001609 · 3.125 in grease cap
Steel press-fit grease cap for a nominal 3-1/8-in hub opening, commonly catalogued for certain eight-bolt hubs; hub-bore measurement still determines fit.
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Fulton BB19800112 · Vinyl protector covers (2-pack)
Replacement flexible covers for a compatible 1.980-in bearing-protector assembly. These fit over a bearing protector, not directly into the bare hub opening like the metal caps above.
Check cover size and item conditionMore trailer wheel-bearing references
If you need a greaseable spring-loaded bearing protector instead of a simple press-fit grease cap, see our trailer bearing protector hub-bore identification guide. For other hub, dust-cap and wheel-hardware designs, see C.E. Smith trailer hub and dust-cap identification. Those reference parts have separate diameters and fitting requirements.
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