CURT Trailer Bearing Protectors: Hub Bore Sizes & Dust Covers
If a trailer hub is missing its bearing protector—or only the grey cover is damaged—the replacement you need depends on both the hub opening and the component that is missing. CURT offers spring-loaded grease-reservoir protectors in several sizes, plus replacement covers sold separately. This reference compares the exact CURT numbers stocked in our catalog so you can distinguish a complete pair from a cover-only pack.
Which CURT size fits the hub opening?
CURT identifies its bearing protector sizes using the hub's nominal inside bore diameter, not the axle's weight rating, wheel diameter or stud pattern. The three complete protector sets offered here fit 1.98-inch, 2.32-inch and 2.44-inch hub openings respectively.
| CURT MPN | Part | Bore or protector size | Contents |
|---|---|---|---|
| 22198 | 1.98-inch bearing protector kit | 1.98 in | 2 metal protectors + 2 outer covers |
| 22232 | 2.32-inch bearing protector kit | 2.32 in | 2 metal protectors + 2 outer covers |
| 22244 | 2.44-inch bearing protector kit | 2.44 in | 2 metal protectors + 2 outer covers |
| 23198 | 1.98-inch protector dust covers | For 1.98-in protector | 2 grey outer covers; no metal protectors |
Replacing the whole assemblyChoose CURT 22198, 22232 or 22244 only after verifying the matching hub bore. Each kit contains two chrome-finish bearing protectors with two outer covers. The spring-loaded reservoir helps keep grease at the wheel hub and provides an additional barrier against moisture and road debris.
Replacing the grey outer capsCURT 23198 contains only two protective grey plastic covers for the 1.98-inch protector family. It does not include the metal grease-reservoir assemblies, wheel bearings, grease seals or a hub. Make sure the original metal protectors are present and serviceable before buying cover-only parts.
Two close-looking sizes are not interchangeable. The 1.98-, 2.32- and 2.44-inch figures are manufacturer-specific fit dimensions. An apparently similar dust cap, wheel size or spindle diameter is not enough to establish a bearing protector fit. Measure the clean hub opening and confirm the original hub or protector number.
What does a bearing protector actually do?
A bearing protector installs at the outer end of a suitable trailer wheel hub in place of an ordinary dust cap. CURT's spring-loaded design contains a small reserve of grease and helps protect the bearing area against water, dirt and road grime. A flexible outer cover shields the exposed end of the protector. Neither part is a replacement for the hub's grease seal, bearings or recommended maintenance.
Before you replace a hub cap or protector
- Find any original part number. Check the old protector, hub or trailer axle documentation. A confirmed matching number is more reliable than appearance alone.
- Check the mounting bore. The precise dimension is the clean inside diameter of the hub opening where the metal protector seats. Measure it using appropriate precision equipment after safely removing the old part according to axle instructions.
- Inspect the wheel bearing system. If grease has leaked, the hub is overheated or the bearing is rough, diagnose that condition rather than simply covering it with a new cap.
- Follow the manufacturer's installation and grease procedure. Confirm the correct seating method and avoid overfilling, which can damage seals. Use the grease specification required by the hub and axle.
- Confirm the replacement package. A 22198 set includes two metal assemblies and two covers. A 23198 pack includes only the two covers. Order the part that addresses the actual damaged or missing component.
Shop CURT bearing protectors and replacement covers
Each card opens the corresponding NewRVParts listing for its exact manufacturer number. These products ship from supplier warehouses; in-person warehouse viewing and pickup are not available.
CURT 23198
1.98-inch protector dust covers
2 grey outer covers; no metal protectors
View matching productOther trailer hub references
For a different manufacturer's protector, consult the Fulton bearing protector comparison or the C.E. Smith hub hardware guide. Similar nominal measurements across brands do not alone confirm the same mounting tolerance or replacement parts.
About NewRVParts
NewRVParts is an online-only source for brand-new RV parts and accessories, truck camper equipment, towing and trailer parts, truck accessories, and marine products. We serve customers throughout Canada and the United States, with products from trusted manufacturers shipped through a large North American distribution network. Shop online for replacement parts, equipment, and accessories delivered directly to your door.
Shop RV Parts