At a Glance
- SKU: 21-35 Billet-Chrome-KITX2

Durable billet aluminum oil bath dust cap pair designed to replace common clear plastic oil caps on compatible threaded trailer oil bath hubs.
This R&P Carriages aftermarket billet aluminum oil bath dust cap pair is a service-friendly replacement solution for compatible trailer oil bath hubs using 2-7/8"-12 threaded caps. Machined from solid aluminum, these caps offer a stronger alternative to common clear plastic oil caps while helping retain hub oil inside the assembly when properly installed with the included sealing components.
Oil bath caps should be matched carefully to the hub thread and cap style before installation. A properly seated cap helps keep lubricant in the hub and contamination out.
Compatibility: Designed as an aftermarket replacement for Dexter 21-35 style oil caps using 2-7/8"-12 threads.
Vehicle / System Fit: Commonly used on trailer oil bath hubs found on many 7,000–9,000 lb trailer axle applications.
Installation Notes: Install with the included sealing components and verify that the cap seats properly before filling, checking, or operating the hub.
Performance Insight: Billet aluminum construction offers a more durable alternative to standard plastic oil caps in heavy-use trailer service.
Selling Brand: R&P Carriages aftermarket replacement cap kit.
Replacement Reference: Dexter 21-35 oil cap style is used as a compatibility and replacement-reference term only.
What This Listing Includes: Two billet aluminum oil bath dust caps with rubber O-rings and rubber center plugs.
Before Ordering: Verify your existing cap thread size, hub type, oil bath cap style, and sealing surface before purchase.
Oil bath hub caps are small parts, but they play an important role in keeping lubricant inside the hub and contamination out. When replacing a cap, inspect the hub threads, O-ring contact area, and oil condition before returning the trailer to service.
Machined from solid aluminum for increased strength compared with common clear plastic oil bath caps.
Designed for compatible trailer oil bath hub systems where proper lubricant retention is critical.
Includes two caps, making this a convenient pair-style replacement for trailer hub service.
Kit includes rubber O-rings and rubber center plugs for proper cap installation.
| Specification | Detail |
|---|---|
| Part Number | 21-35 Billet-Chrome-KITX2 |
| Listing SKU | 21-35 Billet-Chrome-KITX2 |
| Brand | R&P Carriages Aftermarket Replacement |
| Product Type | Oil Bath Dust Cap Pair |
| Quantity Included | 2 Caps / 1 Pair |
| Application | Trailer Oil Bath Hubs |
| Material / Finish | Billet Aluminum / Natural Aluminum Finish |
| Key Measurement | 2-7/8"-12 Thread |
| Cap Style | Threaded Oil Bath Dust Cap |
| Replacement Reference | Dexter 21-35 Oil Cap Style |
| Category | Details |
|---|---|
| Vehicle / System | Trailer Oil Bath Hub System |
| Primary Fit | Hubs requiring 2-7/8"-12 threaded oil bath caps |
| Secondary Fit | Commonly used on oil bath hubs for 7,000–9,000 lb trailer axle applications |
| Notes | May be associated with hub/drum casting references such as 8-219, 8-232, 8-285, and 8-286. Verify exact hub thread and cap style before ordering. |
| Key Dimension | Measurement |
|---|---|
| Thread Size | 2-7/8"-12 |
| Replacement Reference | Dexter 21-35 Oil Cap Style |
| Cap Style | Threaded Oil Bath Dust Cap |
| Quantity | 2 Caps / 1 Pair |
| Quantity | Item |
|---|---|
| 2 | Billet Aluminum Oil Bath Dust Caps |
| Included | Rubber O-rings |
| Included | Rubber Center Plugs |
Selected products are added together. Review the cart and verify kit contents to prevent duplicates. Prices and discounts are determined at checkout.
Have your SKU or manufacturer part number, photos of the original part and mounting, and any critical measurements ready. Capacity, voltage, or bolt pattern can help too.
815-357-3292 · 270 E Jackson St · Seneca, IL 61360
Customer feedback summarized from Google and Yellow Pages. Dates are shown where available.
Ordered trailer repair parts repeatedly; praised fast service, careful packing, and accurate orders.
Found the correct RV keys at a good price with free shipping; the keys worked as expected.
Needed an unusual axle and leaf-spring size; the team listened and helped him sort out the fit.
Praised the OEM and aftermarket selection, discounts, quick shipping, and friendly parts staff.
Got the axle he needed right away, set up with a custom spring perch.
Praised the polite staff and quality welding on a project.
Replacement struts brought a long-used door back to working order.
Had a trailer built to his needs at a fair price, then found parts for two other trailers in stock.
Praised the customer service after working with R&P over several years.
Found the gas shock he wanted at a good price with shipping included.
Received swivel D-rings with backing plates and praised the price, correct order, and service.
The right parts arrived the first time, with fast delivery and helpful staff.
Said project advice and prompt shipping helped finish a trailer project.
Reported helpful service and fast shipment to Germany.
Praised a suspension kit, fair pricing, and good parts.
Was pleased with a replacement trailer cord.
Noted dependable service and products across repeat visits.
Said the axle installation fit perfectly and thanked Josh and the crew.
Praised the crew’s professionalism during a difficult hitch replacement.
Liked the product, price, communication, and shipping.
Said the product description explained what would work for the trailer.
Received the item as described with very fast shipping and plans to return.
Praised accurate description, quick shipping, and clear communication.
Was happy with the product and its price.
Called it a pleasure doing business with R&P.
Was pleased with product quality, quick delivery, and an easy installation.
Was enthusiastic about the products.
Was ready to install the product on every trailer they own.
Expected to buy again after a good experience.
Reported that the newly installed parts were working perfectly.
Said things went well, as they had on previous visits.
Praised clear communication and fair value.
Said the transaction went as expected.
Noted good value, careful packing, and fast shipping.
Found the team professional and easy to work with.
Praised fast shipping and good communication.
Shared appreciation for the owners and their company.
Reported prompt shipping and said they would buy again.
Found R&P easy to deal with.
Praised the people and the service.
Reported a good fit, fair price, accurate listing, and quick shipping.
Received the order a day early and recommended the seller.
Described a no-hassle, professional custom-trailer purchase.
Praised a new trailer, custom additions, helpful staff, and clear pricing.
Found the right hub covers quickly and got helpful maintenance advice.
Said R&P helped their company get back on the road after an axle problem.
Was happy with a dump-trailer purchase after comparing options.
Received clear help choosing brake assemblies and bearing seals, followed by fast shipping.
Found a good deal on a 16-foot dump trailer and planned to return.
Thanked the staff for their patience and recommended the shop.
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