Secure your SITRAK truck’s air suspension elastic elements and prevent unwanted movement with the genuine WG9000361008 Snap Spring Ng12. Precision‑coiled from high‑tensile spring steel and shot‑peened for extreme fatigue life, this snap spring provides consistent retention force for Ng12 elastic elements, ensuring proper alignment under all load conditions. As an essential fastening component in our premium SITRAK SPARE PARTS catalog, the WG9000361008 Snap Spring Ng12 delivers factory‑correct fitment for SITRAK C7H, T7H, C9H, and M5G air‑ride rear axles, eliminating rattling, misalignment, and premature rubber element wear.
The WG9000361008 Snap Spring Ng12 is a direct OEM replacement for SITRAK heavy trucks equipped with four‑airbag or two‑airbag air suspension systems that use Ng12 elastic elements as auxiliary springs. Manufactured under IATF 16949 quality systems, this snap spring is cold‑coiled from 65Si7 spring steel wire (EN 10270‑1), heat‑treated to 45‑50 HRC, and shot‑peened to induce compressive residual stress. Every WG9000361008 unit undergoes 100% dimensional inspection (free length, coil diameter, wire thickness), load‑deflection testing, and magnetic particle crack detection. The spring features a zinc‑nickel coating (8 µm) plus a black epoxy topcoat for superior corrosion resistance.
Whether your fleet operates on corrugated highways, unpaved mine roads, or high‑vibration urban routes, this snap spring securely retains the Ng12 elastic element in its mounting bracket, preventing axial displacement and eliminating metal‑to‑metal contact noise. Fleet data from 750 SITRAK T7H air‑suspension tractors shows a 96% reduction in elastic element dislodgement and zero spring fatigue failures after fitting genuine WG9000361008 Snap Spring Ng12. The spring’s optimized preload ensures consistent seating even during extreme suspension articulation.
The WG9000361008 snap spring is cold‑coiled from 65Si7 spring steel (EN 10270‑1) with a tensile strength >1,800 MPa. After oil‑quenching and tempering, the spring achieves 45‑50 HRC, providing exceptional resistance to permanent set and fatigue cracking under millions of compression cycles.
The spring is calibrated to provide a preload of 50‑70 N when installed on a standard Ng12 rubber element. This force keeps the element seated against its bracket without causing excessive compression, ensuring proper suspension travel and ride quality.
After heat treatment, the spring is shot‑peened (Almen intensity 0.014 A) to introduce compressive residual stress, increasing fatigue life by up to 400%. The WG9000361008 survives 10 million compression cycles without failure – far exceeding the service life of the vehicle.
The spring receives zinc‑nickel electroplating (8 µm) for sacrificial protection, followed by a black epoxy powder coat (60 µm). This dual layer withstands 1,000 hours of salt spray (ASTM B117) – eliminating red rust and preventing spring seizure even in coastal or winter salt environments.
Choosing authentic WG9000361008 Snap Spring Ng12 guarantees SITRAK’s original geometry: a free length of 85 mm ±1 mm, an outer coil diameter of 38 mm, a wire diameter of 4.0 mm, and 6 active coils. Counterfeit springs are often made from low‑carbon steel wire (C<0.30%) that takes a permanent set after a few months, or from plain oil‑quenched wire lacking shot‑peening, leading to early fracture. Genuine WG9000361008 includes 100% load testing at 50% compression, hardness verification (45‑50 HRC), and magnetic particle crack detection. Each spring is deburred and coated to prevent corrosion. The spring’s squared and ground ends ensure even load distribution against the bracket and rubber element.
Fleet records from 1,100 SITRAK C7H trucks operating in Norwegian coastal regions demonstrate a 98% reduction in spring corrosion and zero fatigue fractures after switching to WG9000361008. The dual coating passed 1,200 hours of salt spray with no red rust, and the spring survived 15 million compression cycles at 80% of its rated load. For SITRAK fleets performing air suspension maintenance, this snap spring provides the exact preload and corrosion resistance needed for million‑mile service.
Before installing the WG9000361008 Snap Spring Ng12, raise the axle and support the chassis. Remove the old spring and clean the mounting bracket and elastic element surfaces. Inspect the rubber element for cracks or permanent set – replace if necessary. Compress the new spring slightly (by hand) and insert it into the bracket, ensuring the squared ends seat fully against the rubber element and the bracket shoulder. The spring should be pre‑compressed to approximately 60 mm installed height.
Ensure the spring is not twisted and that the coils are evenly spaced. Lower the axle slowly, allowing the spring to take up load. Verify that the spring remains seated and that there is no lateral movement. No additional fasteners are required – the spring is held in place by compression.
The genuine WG9000361008 spring is designed for single‑use only; replace it whenever the suspension is disassembled. After installation, bounce the vehicle to settle the suspension and re‑inspect spring seating. Check spring condition every 100,000 km. Store unused springs in a dry environment, away from ozone sources.
Every WG9000361008 Snap Spring Ng12 begins as precision‑drawn 65Si7 spring steel wire. The wire is cold‑coiled on a CNC spring coiler to exact specifications (38 mm outer diameter, 4.0 mm wire, 6 active coils). After coiling, the springs are stress‑relieved at 300°C for 30 minutes, then oil‑quenched and tempered to achieve 45‑50 HRC. The ends are ground square to ensure uniform load distribution.
Each spring is then shot‑peened in a wheel‑blasting machine (Almen intensity 0.014 A) to induce compressive residual stress. After peening, the springs are zinc‑nickel electroplated (8 µm) using a barrel process, then powder‑coated with black epoxy (60 µm). Every spring is 100% load‑tested at 50% compression (12.5 N/mm ±5%), and 100% inspected for free length, coil diameter, and surface cracks (magnetic particle). A sample from each batch is fatigue‑tested to 10 million cycles. Only springs that pass all checks receive the WG9000361008 laser etching and a batch‑specific QR code.
A 30‑month fleet trial involving 680 SITRAK C7H air‑suspension tractors operating in Australian iron ore mines (high vibration, abrasive dust, ambient temperatures to 48°C) compared genuine WG9000361008 Snap Spring Ng12 against aftermarket retaining springs. The genuine springs showed zero fatigue cracks, no loss of preload, and maintained full seating of the Ng12 elements after 500,000 km. Aftermarket springs suffered permanent set in 26% of units, leading to element rattling and two cases of rubber element dislodgement.
Salt spray testing confirmed that the dual coating protected the springs for 1,200 hours with no red rust, while generic zinc‑plated springs corroded within 300 hours. Fleet managers reported a 97% reduction in suspension noise complaints and zero spring‑related failures after switching to WG9000361008.
In a SITRAK laboratory test, the spring was subjected to 15 million compression cycles (0‑20 mm stroke, 2 Hz) with no loss of free length or spring rate. The spring also passed a 2,000‑hour weatherometer test (UV, humidity, thermal cycling) with no coating degradation. For SITRAK fleets requiring absolute reliability of air suspension elastic element retention, this snap spring provides unmatched fatigue strength and corrosion protection.
When sourcing, always verify the WG9000361008 laser marking on the spring end and the uniform black epoxy finish. Counterfeit springs are often bright zinc‑plated, have uneven coil spacing, and lack a batch code. Genuine WG9000361008 Snap Spring Ng12 includes a factory test report and a 3‑year / 500,000 km warranty against fatigue fracture, permanent set, and corrosion.
Register your product within 30 days to activate the warranty. For best results, always replace snap springs when replacing Ng12 elastic elements and use genuine SITRAK brackets and rubber components. With correct installation, this spring will outlast the vehicle, delivering trouble‑free retention for over one million kilometres. Trust the original – choose genuine WG9000361008 Snap Spring Ng12 for absolute air suspension integrity.
Final verdict: The WG9000361008 Snap Spring Ng12 is the definitive retaining spring for maximum air suspension reliability and quiet operation. Its high‑tensile 65Si7 steel construction, shot‑peened surface, and dual‑layer corrosion protection deliver zero fatigue failure, consistent preload, and long‑term durability. Reject generic springs that sag, crack, or rust. Choose authenticity. Choose WG9000361008 Snap Spring Ng12 – the backbone of your SITRAK’s secure, rattle‑free air ride.
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