Hyundai Trago Hollow Spring OEM 55131-7L500

Introduction

On Hyundai Trago heavy duty trucks, the hollow spring OEM 55131-7L500 is the core elastic element of the rear tandem (balance) suspension. This rubber-to-metal bonded spring carries the axle load, absorbs road shocks and protects the chassis frame under full-load conditions. When the 55131-7L500 hollow spring cracks, sags or debonds, ride quality and load capacity drop sharply. This guide walks European and North American OEMs and purchasers through its structure, vehicle fitment, cross-reference numbers, failure symptoms and installation tips.

1. Technical Details: Structure, Material and Performance

Part number 55131-7L500 is a hollow spring (also called bolster spring or rubber support) in the rubber-to-metal bonded parts family. The main body is a hollow, cone-shaped natural rubber element vulcanized between two high-strength steel plates with pre-drilled mounting holes for bolting to the suspension bracket and axle housing.

• Hollow-cavity design: the internal cavity creates a progressive spring rate — soft under light load for ride comfort, progressively stiffer under full load for maximum carrying capacity.

• Materials: a high natural rubber (NR) compound provides excellent tear resistance and dynamic fatigue life. Carbon steel plates are phosphated and treated with Chemlok-type bonding agents before one-step vulcanization, so any failure occurs in the rubber body, never at the bond line.

• Advantages over steel helper springs: no metal-to-metal noise, maintenance-free, lighter weight (approx. 9 kg) and stable elasticity from -40°C to +80°C.

This part is manufactured by Hebei Huami New Material Technology Co., Ltd., a company listed on the Beijing Stock Exchange, and exported worldwide through its wholly-owned subsidiary Hebei Tongsource International Trade Co., Ltd. The factory holds IATF 16949, ISO 9001, ISO 14001, TÜV and AEO certifications, and the product is developed to the original 55131-7L500 drawing dimensions to guarantee interchangeability.

2. Vehicle Fitment List

Model / Series	Years	Configuration	Position
Hyundai Trago Dump Truck	2006–2013	6x4 / 8x4	Rear tandem suspension
Hyundai Trago Tractor	2006–2013	6x4	Rear tandem suspension
Hyundai Trago Cargo / Mixer Chassis	2006–2013	6x4 / 8x4 / 10x4	Rear tandem suspension
Hyundai New Power Truck (shared platform)	2004–2010	6x4 / 8x4	Rear axle (verify by VIN)
Hyundai Xcient early transition models	2013–2015	6x4	Rear axle (verify by VIN)

Note: fitment data compiled from public sources; always confirm with the vehicle VIN and the official Hyundai EPC catalog.

3. Cross-Reference Numbers

Number	Type	Remarks
55131-7L500	Hyundai genuine (primary)	Standard format
551317L500	Format variant	No-hyphen format, common in CIS catalogs
55131 7L500	Format variant	Space-separated format
55131-7M501	Adjacent Hyundai number	Upgraded/variant hollow spring on the same platform, approx. 210 x 153 x 148.5 mm — confirm by model
55131-7L5** series	Same series	Related part numbers for different axle-load configurations; send photos and dimensions for matching

4. Typical Failure Symptoms

• Surface or deep cracking: caused by dynamic loading and ozone aging; replace immediately if cracks exceed 10 mm depth.

• Permanent set (sagging): reduced free height, low rear ride height and frequent bottoming-out under load.

• Rubber-to-metal debonding: visible separation at the bond line with knocking noise while driving — a dangerous failure mode, replace in pairs.

• Chunking or local rubber loss: usually from overloading or interference; unbalanced stiffness leads to uneven axle loading and irregular tire wear.

• Degraded damping: increased cab vibration and cargo shaking indicate hardened, aged rubber.

5. Key Specification Table

Item	Specification	Remarks
OEM Number	55131-7L500	Hyundai Trago
Product Name	Hollow Spring / Bolster Spring (Rubber Support)	Rubber-to-metal bonded part
Rubber Material	Natural rubber (NR) based compound	High fatigue and tear resistance
Rubber Hardness	60±5 Shore A (typical)	Customizable 55–70 Shore A
Tensile Strength	≥17 MPa	Typical factory value
Elongation at Break	≥400%	Typical factory value
Dimensions	Approx. Length 200 mm x Width 160 mm	Free height per OEM drawing
Weight	Approx. 9 kg	Including bonded steel plates
Metal Parts	Carbon steel plate, phosphated + bonding agent	One-step vulcanization bonding
Fitting Position	Rear axle (tandem/balance suspension)	—
Working Temperature	-40°C to +80°C	—

6. Installation Notes

1. Lift the vehicle and support the rear axle securely; release suspension load before removing the old part. Never work under a jack alone.

2. Clean rust and old rubber debris from the mounting seats and check that bolt-hole threads are intact.

3. Replace hollow springs in pairs (left and right) to avoid stiffness imbalance across the axle.

4. Tighten bolts to the specified torque in a diagonal sequence and in stages; do not fully tighten with an impact wrench. Re-torque with the vehicle loaded on the ground.

5. Never apply mineral-oil lubricants to the rubber surface; a small amount of soapy water may be used for positioning.

6. Run the vehicle 500 km under load after installation, then inspect for noise, misalignment and bolt loosening.

7. Frequently Asked Questions (FAQ)

Q1: Are 55131-7L500 and 55131-7M501 interchangeable?

A: Both are rear hollow springs on the Trago platform, but dimensions and spring rates differ. Direct interchange is not recommended — confirm by VIN or by measuring the old part.

Q2: How does your part compare with the Korean genuine one?

A: It is developed to the OEM drawing with a comparable NR compound and bonding process. Our IATF 16949 certified factory provides material reports and fatigue test data at a much better price than genuine channels.

Q3: What is the normal service life of this hollow spring?

A: Typically 3–5 years or 300,000–500,000 km under normal loads. Frequent overloading or mining-site conditions shorten this significantly; inspect visually at every service.

Q4: What is your MOQ? Can I get samples first?

A: Standard MOQ is 50–100 pieces. Free or cost-price samples are available (freight collect), with a 7–15 day sample lead time.

Q5: What are your lead time and trade terms?

A: 35–45 days for regular orders. We support FOB Tianjin/Qingdao, CIF and DAP terms, with T/T or L/C payment.

Q6: Do you support OEM/ODM branded packaging?

A: Yes. Neutral packing, customer-branded color boxes, shipping marks, barcodes and market-specific labels are all available.

Q7: How do I know my hollow spring needs replacement?

A: Replace it when you see deep cracks, obvious sagging, debonding noise or irregular rear tire wear — and always replace in pairs.

Q8: Which other Hyundai truck rubber parts can you supply?

A: We cover the full range for Hyundai Trago/Xcient platforms: engine mounts, V-torque rod bushings, balance shaft bushings and cab mounts. Send your part list for a consolidated quotation.

8. Conclusion & Call to Action

The hollow spring 55131-7L500 is critical to the reliability of the Hyundai Trago rear suspension. Sourcing from Hebei Tongsource International Trade Co., Ltd. — the wholly-owned export subsidiary of Beijing Stock Exchange-listed Hebei Huami New Material Technology Co., Ltd. — gives you direct factory pricing, IATF 16949 quality assurance and responsive export service.

Contact us today for a free sample, full specification sheet and the latest quotation of 55131-7L500. Send your inquiry via tongsource.com and our export team will reply within 24 hours.