At a Glance
- SKU: RP9-123-01
PRODUCT INFORMATION
Product Details
Trailer Axle Brake Drum / 9K 10K GD 13G Applications
M-Parts Brake Drum for 10K GD & 13G Axles — 12.25" × 3.375" — RP9-123-01
M-Parts machined brake drum for compatible Dexter-style 9K, 10K General Duty, and 13G axle applications manufactured after July 2009. Designed for systems using 12.25" × 3.375" brake assemblies and an 8-stud, 7.5" bolt circle configuration.
Part Number: RP9-123-01 12.25" × 3.375" Brake Size Replaces Dexter 009-123-03
Overview
This M-Parts brake drum is a replacement drum for compatible 9K, 10K General Duty, and 13G axle brake systems built after the July 2009 component change. It is intended for trailer service where the axle, brake assembly size, bolt circle, and drum configuration match the listed specifications.
R&P Service Insight
Brake drums must match both the brake assembly size and the axle hub/brake system design. This drum is for the newer post-July 2009 Dexter-style configuration and should not be matched only by axle capacity.
- Brake Size Match: Confirm your brake assembly is 12.25" × 3.375" before ordering.
- Bolt Circle Check: Verify the 8-stud, 7.5" bolt circle configuration on your existing setup.
- Axle Date Matters: Dexter made major 9K and 10K GD component changes in 2009, so axle build date and part style should be checked carefully.
R&P Knowledge Hub
Compatibility: Commonly used on 9K, 10K General Duty, and 13G axle applications manufactured after July 2009 where specifications match.
Vehicle / System Fit: Trailer axle brake drum applications using 12.25" × 3.375" brake assemblies and an 8-stud, 7.5" bolt circle configuration.
Installation Notes: Verify axle tag, brake size, bolt circle, drum design, and existing part number before installation.
Performance Insight: A correctly matched drum supports proper shoe contact, braking surface alignment, and service fit on compatible heavy-duty trailer brake systems.
Brand & Fitment Note
Selling Brand: M-Parts
Application Reference: Dexter names and part numbers in this listing are used for compatibility and application reference only where the listed specifications match.
What This Means: This listing is for an M-Parts brake drum, not a guaranteed Dexter OEM-branded item unless specifically stated and verified.
Before Ordering: Verify axle build date, axle tag, brake size, bolt circle, hub/drum style, and included components before installation.
R&P Repair Insight
Older Dexter 8-288, 8-232, and 8-256 series two-piece drum setups are not the same as this post-2009 drum style. Always compare your existing drum and axle information before ordering.
- Date Break Check: Confirm the axle was manufactured after July 2009.
- Old-Style Drum Check: Do not use this as an interchange for older 8-288, 8-232, or 8-256 series two-piece drums.
- Parts Shown in Diagrams: This listing is for the brake drum only; related hub, brake, bearing, seal, stud, or hardware components are not included unless separately stated.
Features
Replacement for Dexter 009-123-03
Listed as a replacement brake drum for Dexter 009-123-03 applications where axle date, brake size, and drum configuration match.
Post-July 2009 Application
Used with newer 9K, 10K General Duty, and 13G axle brake systems manufactured after the 2009 component change.
12.25" × 3.375" Brake Size
Designed for compatible brake assemblies using a 12.25" brake diameter and 3.375" brake width.
8-Stud 7.5" Bolt Circle
Matches applications using an 8-stud configuration with a 7.5" bolt circle pattern.
Specifications
| Specification | Detail |
|---|---|
| Part Number | RP9-123-01 |
| Brand | M-Parts |
| Product Type | Brake drum |
| Application | Trailer axle brake drum replacement |
| Material / Finish | Machined brake drum; finish not specified |
| Brake Diameter | 12.25" |
| Brake Width | 3.375" |
| Bolt Circle | 8-stud configuration, 7.5" bolt circle |
| Replaces Dexter | 009-123-03 |
Fitment / Application
| Category | Details |
|---|---|
| Vehicle / System | Heavy-duty trailer axle brake drum system |
| Primary Fit | Dexter-style 9K, 10K General Duty, and 13G axle applications manufactured after July 2009 |
| Brake Assembly Match | 12.25" × 3.375" brake assemblies |
| Notes | Older 8-288, 8-232, and 8-256 series two-piece drum setups will not interchange with this post-2009 drum. Verify axle tag, measurements, and existing drum configuration before ordering. |
Included Components
| Quantity | Item |
|---|---|
| 1 | M-Parts brake drum, part number RP9-123-01 |
| Not included | Hub, brake assembly, bearings, seals, wheel studs, wheel nuts, mounting hardware, or other related components unless separately stated |
Verify axle tag, axle build date, brake size, bolt circle, drum configuration, and included components before installation. Dexter names and part numbers are used as compatibility references only. This listing is for the brake drum only.
M-Parts RP9-123-01 brake drum, Dexter 009-123-03 replacement brake drum, 12.25 x 3.375 brake drum, 10K GD brake drum, 13G axle brake drum, 9K trailer axle brake drum, 8 lug 7.5 bolt circle brake drum, post July 2009 Dexter style brake drum, heavy duty trailer brake drum
Related Parts & Kits
Check fitment, measurements, and kit contents before ordering. Related parts may not be required for your repair.
Looking up part numbers in our catalog…
Your repair list1 item selected
Selected products are added together. Review the cart and verify kit contents to prevent duplicates. Prices and discounts are determined at checkout.
BEHIND THIS LISTING
PHOTOGRAPHY & RESEARCH
Ariah Granados
DIGITAL PRESENTATION & DEVELOPMENT
Ken Martin
ONLINE SALES & QUALITY ASSURANCE
Rayn Fisher
WE’RE HERE TO HELP
Not sure it fits?
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 REVIEWS
Leave a Google review
Good people. Real trailer work.
Customer feedback summarized from Google and Yellow Pages. Dates are shown where available.
TRAILER PARTSGOOGLE
Ordered trailer repair parts repeatedly; praised fast service, careful packing, and accurate orders.
RV KEYSGOOGLE
Found the correct RV keys at a good price with free shipping; the keys worked as expected.
AXLE & LEAF SPRINGSGOOGLE
Needed an unusual axle and leaf-spring size; the team listened and helped him sort out the fit.
PARTS & SHIPPINGGOOGLE
Praised the OEM and aftermarket selection, discounts, quick shipping, and friendly parts staff.
CUSTOM AXLEGOOGLE
Got the axle he needed right away, set up with a custom spring perch.
WELDINGGOOGLE
Praised the polite staff and quality welding on a project.
GAS STRUTGOOGLE
Replacement struts brought a long-used door back to working order.
CUSTOM TRAILERGOOGLE
Had a trailer built to his needs at a fair price, then found parts for two other trailers in stock.
CUSTOMER SERVICEGOOGLE
Praised the customer service after working with R&P over several years.
GAS SHOCKGOOGLE
Found the gas shock he wanted at a good price with shipping included.
CARGO TIE-DOWNGOOGLE
Received swivel D-rings with backing plates and praised the price, correct order, and service.
PARTS DELIVERYGOOGLE
The right parts arrived the first time, with fast delivery and helpful staff.
PROJECT HELPYELLOW PAGES
Said project advice and prompt shipping helped finish a trailer project.
SHIPPINGYELLOW PAGES
Reported helpful service and fast shipment to Germany.
SUSPENSION KITYELLOW PAGES
Praised a suspension kit, fair pricing, and good parts.
TRAILER CORDYELLOW PAGES
Was pleased with a replacement trailer cord.
SERVICE & PARTSYELLOW PAGES
Noted dependable service and products across repeat visits.
AXLE INSTALLATIONYELLOW PAGES
Said the axle installation fit perfectly and thanked Josh and the crew.
HITCH REPLACEMENTYELLOW PAGES
Praised the crew’s professionalism during a difficult hitch replacement.
PRICE & SERVICEYELLOW PAGES
Liked the product, price, communication, and shipping.
LISTING INFORMATIONYELLOW PAGES
Said the product description explained what would work for the trailer.
PRODUCT & SHIPPINGYELLOW PAGES
Received the item as described with very fast shipping and plans to return.
COMMUNICATION & SHIPPINGYELLOW PAGES
Praised accurate description, quick shipping, and clear communication.
PRICE & PRODUCTYELLOW PAGES
Was happy with the product and its price.
SELLER EXPERIENCEYELLOW PAGES
Called it a pleasure doing business with R&P.
INSTALLATIONYELLOW PAGES
Was pleased with product quality, quick delivery, and an easy installation.
PRODUCTSYELLOW PAGES
Was enthusiastic about the products.
DURABILITYYELLOW PAGES
Was ready to install the product on every trailer they own.
REPEAT CUSTOMERYELLOW PAGES
Expected to buy again after a good experience.
INSTALLED PARTYELLOW PAGES
Reported that the newly installed parts were working perfectly.
REPEAT CUSTOMERYELLOW PAGES
Said things went well, as they had on previous visits.
COMMUNICATION & VALUEYELLOW PAGES
Praised clear communication and fair value.
TRANSACTIONYELLOW PAGES
Said the transaction went as expected.
PRICE & PACKAGINGYELLOW PAGES
Noted good value, careful packing, and fast shipping.
PROFESSIONAL SERVICEYELLOW PAGES
Found the team professional and easy to work with.
COMMUNICATION & SHIPPINGYELLOW PAGES
Praised fast shipping and good communication.
TEAMYELLOW PAGES
Shared appreciation for the owners and their company.
SHIPPINGYELLOW PAGES
Reported prompt shipping and said they would buy again.
CUSTOMER SERVICEYELLOW PAGES
Found R&P easy to deal with.
SERVICEYELLOW PAGES
Praised the people and the service.
FIT & SHIPPINGYELLOW PAGES
Reported a good fit, fair price, accurate listing, and quick shipping.
DELIVERYYELLOW PAGES
Received the order a day early and recommended the seller.
CUSTOM TRAILERYELLOW PAGES
Described a no-hassle, professional custom-trailer purchase.
TRAILER PURCHASEYELLOW PAGES
Praised a new trailer, custom additions, helpful staff, and clear pricing.
HUB COVERSYELLOW PAGES
Found the right hub covers quickly and got helpful maintenance advice.
AXLE HELPYELLOW PAGES
Said R&P helped their company get back on the road after an axle problem.
DUMP TRAILERYELLOW PAGES
Was happy with a dump-trailer purchase after comparing options.
BRAKES, DRUMS & SEALSYELLOW PAGES
Received clear help choosing brake assemblies and bearing seals, followed by fast shipping.
DUMP TRAILERYELLOW PAGES
Found a good deal on a 16-foot dump trailer and planned to return.
FRIENDLY SERVICEYELLOW PAGES
Thanked the staff for their patience and recommended the shop.
Showing 3 of 50
Need help with this part? Send photos, part numbers, and measurements. We’ll help you narrow it down.