The suspension system is the backbone of your truck’s ride quality and load-bearing capability, and the spring pin assembly is a critical pivot point. The WG9000520040 LEFT SPRING PIN ASSY from HOWO is engineered to deliver exceptional strength, precise alignment, and outstanding wear resistance, ensuring that your leaf springs operate smoothly and reliably under the heaviest loads. As a vital Howo/Sitrak truck parts component, this left spring pin assembly is forged from high-grade alloy steel, precision-machined to exacting tolerances, and heat-treated for optimal hardness and toughness. Its robust design eliminates play, reduces friction, and maintains proper suspension geometry, contributing to stable handling and extended tire life. Whether you are rebuilding a front axle or replacing worn suspension components, the WG9000520040 guarantees a perfect factory fit, superior durability, and consistent performance – making it the trusted choice for professional workshops and fleet maintenance teams worldwide.
The left spring pin assembly is the pivot that connects the leaf spring to the axle or frame, allowing vertical articulation while maintaining lateral stability. Over time, this component is subjected to immense cyclic loads, shock forces, and abrasive contaminants. A worn or loose spring pin leads to axle misalignment, uneven tire wear, compromised ride comfort, and even dangerous handling characteristics. HOWO has designed the WG9000520040 with a hardened steel shank and a precision-ground bearing surface that minimizes friction and wear. The included bushings and washers are made from oil-impregnated bronze, providing self-lubricating properties that reduce maintenance intervals. With this assembly, you restore the original suspension geometry, improve steering response, and protect other suspension components from premature failure.
High Load
Capacity
Precision
Fitment
OEM Grade
Genuine HOWO
Wear‑Resistant
Long Life
Accurate engineering data is essential for proper selection and installation. The WG9000520040 is manufactured to the highest OEM standards, guaranteeing a seamless replacement for your HOWO truck’s left spring pin assembly.
| Parameter | Specification | Detail |
|---|---|---|
| OEM Number | WG9000520040 | Exact Match |
| Part Name | LEFT SPRING PIN ASSY | HOWO Genuine |
| Brand | HOWO | Original Equipment |
| Application | HOWO T7H / A7 / Front suspension | Leaf spring pivot |
| Material | Alloy steel (40Cr) | Forged & hardened |
| Pin Diameter | 36 mm | Precision ground |
| Overall Length | 180 mm | Including bushings |
| Hardness (core) | 28–32 HRC | Toughness |
| Surface Hardness | 55–60 HRC (case) | Wear resistant |
| Bushing Material | Oil‑impregnated bronze | Self‑lubricating |
| Max Load Capacity | 180 kN (static) | Heavy‑duty |
| Weight | 2.8 kg | Complete assembly |
| Warranty | 12 Months | Manufacturer Guarantee |
The WG9000520040 is produced through a multi‑step manufacturing process that begins with hot‑forging of premium alloy steel to align the grain structure for maximum strength. The forged blank is then annealed to relieve internal stresses before CNC turning and grinding operations bring the pin to its final dimensions with an accuracy of ±0.02 mm. The critical bearing surfaces are ground to a mirror finish (Ra 0.4) to reduce friction and extend the life of the mating bushings.
A carburizing heat treatment is applied to achieve a hard, wear‑resistant outer case while maintaining a tough, ductile core that can absorb shock loads without fracturing. The assembly includes high‑quality bronze bushings that are pressed into the spring eyes and reamed to the correct clearance, ensuring smooth articulation without excessive play. The included grease fittings facilitate regular lubrication, further reducing wear. Each assembly is inspected for hardness, dimensional accuracy, and concentricity using coordinate measuring machines, guaranteeing that the WG9000520040 meets HOWO’s stringent quality standards. This meticulous engineering ensures that your suspension performs reliably, mile after mile.
The WG9000520040 is specifically designed for HOWO heavy‑duty trucks, including T7H, A7, and derivative models equipped with the front leaf spring suspension. It is used on the left side (driver side) of the front axle, connecting the spring eye to the hanger bracket. The assembly is a direct replacement for the original part, with identical dimensions, mounting provisions, and bushing sizes. It is compatible with both standard and heavy‑duty spring packs.
This spring pin assembly is also compatible with many Sinotruk and other commercial vehicles that share the same suspension architecture. To confirm fitment, always cross‑reference the OEM number on your existing assembly with WG9000520040. If they match, this component will integrate seamlessly. Keeping this assembly in your spare parts inventory ensures rapid suspension repairs, minimizing downtime and preserving vehicle safety and ride quality.
HOWO T7H
Primary Fitment
HOWO A7
Also Compatible
Leaf Spring
Front Suspension
Direct Replacement
No Modifications
Replacing a worn or damaged spring pin assembly with the WG9000520040 yields immediate improvements in ride quality and vehicle stability. The tight clearance between the pin and bushings eliminates excessive axle movement, reducing steering wander and improving straight‑line tracking. The reduced friction also results in smoother suspension articulation, which enhances tire contact with the road, improving braking and cornering performance.
The robust construction ensures that the assembly can withstand the high static and dynamic loads encountered during heavy hauling and off‑road operation. The self‑lubricating bushings reduce the frequency of grease applications, simplifying maintenance. For fleet operators, a reliable spring pin assembly reduces the risk of spring‑related failures, lowers tire wear, and extends the life of shock absorbers. By investing in the WG9000520040, you ensure that your HOWO truck handles predictably, reduces driver fatigue, and maximizes payload safety.
Installing the WG9000520040 Left Spring Pin Assy is a task that requires proper tools and safety precautions. Begin by safely supporting the vehicle on stands and relieving the weight from the leaf spring. Remove the old spring pin by unfastening the retaining bolts and driving the pin out using a suitable drift and hammer.
Clean the hanger and spring eye thoroughly, removing all rust and old grease. Inspect the spring eye and hanger for excessive wear or ovality; if damaged, repair or replace them before installation. Lubricate the new pin and bushings with clean chassis grease, then insert the pin through the hanger and spring eye, ensuring the grease fitting is accessible. Install and torque the retaining bolts to the manufacturer’s specification, and fill the grease fitting until fresh grease appears. After installation, check for any lateral play; there should be minimal to none. Periodically lubricate the assembly according to the vehicle’s maintenance schedule. With proper care, the WG9000520040 will provide years of reliable service.
Pro Tip: When installing, always check the torque of the retaining bolts after the first 500 kilometers of operation, as new components settle. The WG9000520040 is designed to work with grade 10.9 fasteners; use new hardware if the old bolts are corroded or worn.
Genuine HOWO components are engineered to the highest standards, and the WG9000520040 Left Spring Pin Assy is no exception. Aftermarket assemblies often use inferior steel, imprecise machining, or poor‑quality bushings, leading to accelerated wear, noise, and premature failure. HOWO’s assembly is manufactured using the same materials and processes as the original equipment, guaranteeing a perfect fit and reliable performance.
By choosing the WG9000520040, you benefit from HOWO’s rigorous validation, which includes fatigue testing, corrosion resistance, and load‑cycle testing. This ensures that the assembly meets the demanding requirements of heavy‑duty trucking. Moreover, genuine parts are backed by a comprehensive warranty and supported by HOWO’s global network, giving you confidence in your purchase and long‑term peace of mind.
OEM Authentic
Factory Quality
Long Service
Extended Life
Global Standard
Trusted Worldwide
Q: Which vehicles use the WG9000520040?
A: It is designed for HOWO T7H, A7, and other models with front leaf spring suspension, as well as many Sinotruk trucks with the same axle design.
Q: What are the symptoms of a worn spring pin assembly?
A: Excessive axle movement, clunking noises over bumps, uneven tire wear, steering wander, and a loose feeling in the front suspension are common indicators.
Q: Does this assembly come with bushings?
A: Yes, the WG9000520040 includes the pin, bushings, washers, and retaining hardware – everything you need for a complete replacement.
Q: How do I verify the correct part?
A: Check the OEM number on your existing assembly. If it matches WG9000520040, this is the exact replacement. Consult your vehicle’s parts manual for additional confirmation.
Order your WG9000520040 Left Spring Pin Assy today! Explore our complete selection of genuine HOWO and Sinotruk suspension components at Howo/Sitrak truck parts and keep your front axle precisely aligned and reliably supported.
The WG9000520040 Left Spring Pin Assy from HOWO is a testament to robust engineering and meticulous manufacturing. By choosing this genuine component, you ensure that your vehicle’s suspension remains stable, responsive, and safe, protecting your cargo and enhancing driver comfort. Whether you are a professional mechanic or a fleet manager, this assembly offers the strength, precision, and durability required for modern heavy‑duty trucks. Trust HOWO – the benchmark for excellence in heavy‑duty truck components – and experience the difference that genuine quality makes.
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