8,000 lb Narrow Trailer Axle Beam - 79" Hub Face - 3.5" Tube with Perches
Heavy-duty 8,000 lb narrow trailer axle beam kit with a 79 inch hub face measurement, 3.5 inch axle tube, and included loose spring perches for custom spring center placement.
Overview
This 8,000 lb D80N narrow trailer axle beam kit is built for trailer repair, replacement, and fabrication work where a 79 inch hub face measurement and 3.5 inch axle tube are required. The kit includes loose spring perches so the axle can be set up to match the trailer’s actual spring center measurement before welding and final installation.
R&P Service Insight
Axle beam fitment depends on real measurements, not guesswork. Hub face, tube size, capacity, camber orientation, and spring center all need to be verified before installation.
- Hub Face Matters: This axle beam is listed with a 79 inch hub face measurement. Match this against the trailer’s required hub face dimension before ordering.
- Loose Perches: The included spring perches ship loose by default so they can be positioned to the correct spring center before welding.
- Installation Required: This axle must not be placed into service until the perches are properly measured, squared, and welded to the axle tube.
R&P Knowledge Hub
Compatibility: Designed for trailer applications requiring an 8,000 lb D80N narrow axle beam with 79 inch hub face and 3.5 inch axle tube dimensions.
Vehicle / System Fit: Leaf spring trailer suspension systems where axle capacity, hub face, tube diameter, and spring center setup match the trailer.
Installation Notes: Spring perches are included loose by default and must be welded at the correct Spring Center measurement before the axle is used.
Performance Insight: Loose perch kits allow spring center placement to be matched to the trailer, but the axle is not road-ready until the perches are properly welded.
Brand & Fitment Note
Selling Brand: R&P Carriages
Application Reference: Any axle series, OEM, or platform names in this listing describe compatibility, fitment target, or application style only where supported by verified dimensions, mounting points, and configuration details.
What This Means: This listing is for a R&P Carriages trailer axle beam kit, not a guaranteed OEM-branded item unless specifically stated and verified.
Before Ordering: Verify hub face, axle capacity, tube diameter, spring center, camber orientation, brake/hub compatibility, and included components before installation.
R&P Repair Insight
This axle beam is a measurement-sensitive running gear part. The axle may physically resemble other 8K beams, but the correct replacement depends on exact trailer dimensions and component compatibility.
- Check Hub Face: Confirm the required hub face measurement is 79 inches before ordering.
- Check Spring Center: Measure center-to-center at the leaf springs or existing spring seats before requesting welded perches.
- Check Related Components: Hubs, drums, brakes, bearings, seals, U-bolts, springs, and mounting hardware must match the axle setup and are not included unless specifically listed.
Features
8,000 lb Axle Beam Rating
Built for heavy-duty trailer running gear applications requiring an 8,000 lb axle beam configuration.
79" Hub Face Measurement
Listed with a 79 inch hub face dimension for narrow trailer axle replacement or build applications.
3.5" Axle Tube
Uses a 3.5 inch axle tube, a key specification that must be matched with compatible suspension and mounting components.
Loose Perch Kit Setup
Includes loose spring perches so the spring center can be set to the trailer’s required center-to-center measurement before welding.
Specifications
| Specification | Detail |
|---|---|
| Part Number | 8000-79-D80N-35-KIT |
| Brand | R&P Carriages |
| Product Type | Trailer axle beam kit with loose spring perches |
| Axle Capacity | 8,000 lb |
| Axle Series / Style | D80N narrow axle beam |
| Hub Face | 79 inches |
| Tube Diameter | 3.5 inches |
| Spring Perches | Included loose by default; not welded unless requested, measured, and confirmed before shipment |
| Finish | Verify current finish before ordering if finish is critical to the application |
| Not Included | Hubs, drums, brakes, bearings, seals, U-bolts, leaf springs, wheels, tires, and mounting hardware unless specifically added |
Fitment / Application
| Category | Details |
|---|---|
| Vehicle / System | Leaf spring trailer suspension running gear |
| Primary Fit | Trailers requiring an 8,000 lb D80N narrow axle beam with 79 inch hub face and 3.5 inch axle tube |
| Spring Center | Perches are loose so Spring Center must be measured and set before welding |
| Notes | Measure the existing axle and trailer before ordering. Do not assume fitment based only on capacity or trailer width. |
Included Components
| Quantity | Item |
|---|---|
| 1 | 8,000 lb D80N narrow trailer axle beam, 79 inch hub face, 3.5 inch tube |
| 2 | Loose spring perches / spring seats for weld-on installation |
| Included | -KIT configuration for spring center setup during installation |
| Not Included | Hubs, drums, brakes, bearings, seals, U-bolts, leaf springs, wheels, tires, and related mounting hardware unless separately listed |
What Comes in the -KIT: Spring Perches Are Included Loose
This -KIT includes the axle beam and loose spring perches / spring seats. The spring perches are included as separate pieces. Included does not mean welded.
Spring perches ship loose by default. They are not welded to the axle tube before shipment unless the customer specifically requests perch welding in the order notes, provides the correct Spring Center measurement, and R&P confirms the weld-on request before the axle ships.
Repetition matters: If the listing says “spring perches included,” that means loose spring perches are included with the kit. It does not mean the spring perches are already installed, welded, or ready for towing.
When Will R&P Weld the Spring Perches?
R&P may weld the spring perches before shipment only when the order clearly gives us the information needed to do it correctly.
- The customer must request welded spring perches in the order notes.
- The customer must provide the Spring Center measurement.
- R&P must confirm the weld-on request before shipment.
How to Find Your Spring Center Measurement
Spring Center is the distance from the center of one leaf spring to the center of the opposite leaf spring. This is the measurement used to locate where the spring perches need to be welded on the axle tube.
- Best method with old axle: Measure from the center of one existing spring perch / spring seat to the center of the opposite spring perch / spring seat.
- Best method from the trailer: Measure from the centerline of the left leaf spring pack to the centerline of the right leaf spring pack where the axle sits.
- Leaf spring center bolt method: Measure from the center of the center bolt / locating pin on one spring pack to the center of the center bolt / locating pin on the other spring pack.
- Do not measure outside-to-outside. Spring Center is a center-to-center measurement.
- Do not guess from deck width. Deck width can be helpful context, but it is not a substitute for the actual Spring Center measurement.
Axle Measurement Diagram
Use the axle measurement diagram below as a visual reference while confirming axle dimensions and installation details. Spring Center must still be measured center-to-center at the trailer’s leaf springs or existing spring perches.
Why Welding the Perches Matters
This image shows a real-world installation problem where loose spring perches were not welded before use and brake wiring was torn out. This is exactly why the axle must not be installed, towed, or placed into service while the spring perches are still loose.
Loose perches can allow the axle to move or rotate out of its intended installed position. That can damage brake wiring, brake components, suspension parts, tires, and the trailer. The perches must be properly welded before road use.
| Question | Answer |
|---|---|
| Are spring perches included in the -KIT? | Yes. The spring perches / spring seats are included as loose parts. |
| Are the spring perches welded on by default? | No. They ship loose by default. |
| Can R&P weld the perches before shipping? | Only if the customer requests it in the order notes, provides the correct Spring Center measurement, and R&P confirms the request before shipment. |
| What measurement is needed for welding? | Spring Center: center of one leaf spring / spring perch to the center of the opposite leaf spring / spring perch. |
| Can the axle be used with loose perches? | No. Do not install, tow, or place the axle in service until the perches are properly welded. |
| What can happen if perches are not welded? | Loose perches can allow the axle to move or rotate, which can damage brake wiring, brake parts, suspension components, tires, and the trailer. |
| Which way does camber face? | If the axle is cambered, the arch goes up in the middle when installed. |
Order Note Wording Customers Can Use
Customers who want R&P to weld the spring perches should put clear instructions in the order notes before checkout.
