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Precision secondary retaining ring for shaft component security – The OEM SPYJ0000002036 2nd Ring is a high‑performance external circlip designed to provide a secondary axial lock for gears, bearings, and other shaft‑mounted components in heavy‑duty transmissions and axles. Manufactured from premium spring steel with a precisely controlled elastic fit, this ring ensures reliable positioning even under extreme vibration and shock loads. For guaranteed compatibility and performance, always choose genuine Sinotruk Homan parts.
The SPYJ0000002036 2nd ring (external snap ring) is dimensioned to fit shafts with a nominal groove diameter of approximately 50 mm and has a cross‑sectional thickness of 2.5 mm. Its open‑ended, compressed‑to‑install design allows fast assembly and disassembly using standard circlip pliers, making it a cost‑effective and reliable solution for secondary axial positioning.
The SPYJ0000002036 2nd ring is a stamped external retaining ring manufactured from high‑carbon spring steel (grade 65Mn or equivalent). It is through‑hardened to 44‑51 HRC to provide excellent elasticity and resistance to permanent deformation. The ring is designed to be seated in a precision‑machined groove on a shaft, where it expands to exert a constant radial force, holding the ring securely in place while providing a rigid axial stop. As a “2nd ring,” it is typically used as an additional safety lock behind a primary retaining ring, ensuring that even if the primary ring fails or shifts, the secondary ring maintains axial component positioning.
This specific size is commonly used in SINOTRUK Homan gearboxes, power take‑off units, and rear axle assemblies to secure gears, bearings, and synchroniser assemblies. The elastic deformation of the ring allows it to be quickly installed and removed with standard circlip pliers, simplifying both assembly and maintenance. The double ring arrangement (primary plus 2nd ring) is a hallmark of SINOTRUK Homan’s commitment to fail‑safe engineering in critical driveline applications.
Compared to ordinary stamped rings, the genuine SPYJ0000002036 offers superior fatigue resistance, tighter dimensional tolerances (±0.05 mm on diameter), and a phosphate coating that resists corrosion and reduces friction during installation. The ring’s edges are deburred and chamfered to prevent damage to the shaft or housing, and the gap is carefully controlled to ensure uniform clamping force around the entire circumference. The secondary ring is often marked with a distinct colour or groove to differentiate it from the primary ring.
Acts as a secondary axial lock behind the primary retaining ring, providing fail‑safe protection in case of primary ring failure or loosening.
Made from vacuum‑degassed 65Mn steel, hardened and tempered for optimum elasticity and resistance to permanent deformation.
Manganese phosphate coating provides excellent rust protection and reduces friction during assembly, preventing galling of the shaft groove.
| OEM Number | SPYJ0000002036 |
| Product Name | 2nd Ring (Secondary External Retaining Ring / Circlip) |
| Brand | SINOTRUK Homan |
| Shaft Diameter (Nominal) | 50 mm (approx.) |
| Wire Thickness (t) | 2.5 mm |
| Free Internal Diameter (unfitted) | 50.0 mm ± 0.2 mm |
| Groove Diameter (Shaft) | 50.1 mm ± 0.05 mm (recommended) |
| Material | Spring steel (65Mn or 1.0605), hardened to 44‑51 HRC |
| Surface Finish | Manganese phosphate coating (15‑25 μm), oil impregnated |
| Max Thrust Load (static) | 7.5 kN (1,690 lbf) |
| Fatigue Limit | 5.4 kN (1,210 lbf) at 1,000,000 cycles |
| Operating Temperature Range | -40°C to +150°C |
| Recommended Gap | 4.5 mm ± 0.5 mm between ends (uncompressed) |
| Applications | Secondary locking for gearbox shafts, PTO gear retention, bearing axial positioning, synchroniser assembly |
| Compatible Models | SINOTRUK HOWO, A7, T7H, C7H gearboxes, ZF transmissions, Fast 12J series |
The SPYJ0000002036 2nd ring is manufactured using a high‑speed stamping process from pre‑tempered spring steel strip. After stamping, the rings are heat‑treated in a continuous mesh‑belt furnace to achieve uniform hardness (44‑51 HRC) without decarburisation. The rings are then tumble‑deburred and phosphated, followed by oil‑dipping to provide temporary lubrication and corrosion protection. The secondary ring often bears a distinct marking (such as two dots or a groove) to differentiate it from the primary ring, aiding assembly line workers in correct placement.
The elastic deformation of the ring is engineered to provide a constant radial outward force when compressed into the shaft groove. This force ensures that the ring remains seated even under severe vibration or shock loads. The open ends are chamfered and rounded to facilitate easy installation with circlip pliers and to prevent snagging on mating components. When used as a 2nd ring, it is installed in a secondary groove located immediately behind the primary groove, creating a mechanical backup that prevents axial movement even if the primary ring becomes dislodged or fatigued.
Each ring is 100% inspected for free diameter, gap width, thickness, and hardness. Random samples are subjected to a 500,000‑cycle dynamic load test (axial reciprocation at 5 kN) and a 240‑hour salt spray test (ASTM B117). The ring meets or exceeds the requirements of DIN 471 (external retaining rings) and SINOTRUK Homan engineering standard Q/SQ 1012. A batch number laser‑etched on the flat face provides full traceability.
The 65Mn spring steel provides an excellent combination of strength and ductility. The heat treatment produces a fine‑grained martensitic structure with good elasticity and resistance to set. The phosphate coating not only prevents rust but also acts as a micro‑reservoir for lubricant, reducing friction between the ring and the groove.
The ring is designed to be used in oil‑splashed environments (e.g., gearboxes) where constant immersion accelerates corrosion protection. For dry applications, the phosphate coating alone provides adequate protection for the life of the component. The secondary ring’s slightly different geometry ensures that it does not interfere with the primary ring’s function while still providing a full‑strength axial lock.
The SPYJ0000002036 2nd ring is a direct replacement for the original secondary retaining ring in SINOTRUK Homan gearboxes. Installation requires a pair of external circlip pliers with tips sized for 2.5 mm holes. The primary ring is installed first into its groove; then the secondary ring is compressed and inserted into the secondary groove, located axially behind the primary groove. Ensure that the secondary ring is fully seated and that there is a small visible gap between the two rings to prevent mutual interference.
Before installation, inspect both shaft grooves for burrs or damage; the primary groove width should be 2.55‑2.65 mm, the secondary groove slightly different if specified. If the grooves are worn, the rings may not seat properly, leading to axial movement. Always replace both rings as a set when servicing the assembly.
1) Thoroughly clean the shaft grooves and the surrounding area; remove any old grease or debris. 2) Select the correct circlip pliers with tips that fit the holes of the ring. 3) Install the primary retaining ring first into its designated groove, ensuring it is fully seated.
4) Compress the secondary ring using the pliers, taking care not to over‑expand or twist the ring. 5) Guide the compressed secondary ring into the secondary groove (located behind the primary ring) and release the pliers slowly. 6) Using a flat punch, tap the ring gently around its circumference to ensure it is fully seated in the bottom of the groove.
7) Check that the secondary ring does not protrude above the groove and that there is a small visible gap between the primary and secondary rings (typically 0.2‑0.5 mm). 8) After assembly, rotate the shaft by hand to ensure that the rings do not interfere with adjacent components. 9) If the ring is part of a gearbox rebuild, fill with the specified lubricant before final assembly.
The SPYJ0000002036 2nd ring requires no regular maintenance, but it should be inspected during gearbox overhauls. Signs of failure: a broken ring, a ring that has lost its spring tension (no longer snaps into the groove), or a ring that has become dislodged (causing axial float). If either the primary or secondary ring is damaged, replace both rings as a set.
Never reuse a ring that has been distorted during removal – the elastic limit may have been exceeded, leading to premature failure. Always replace the shaft seal and any damaged bearings when replacing the rings. For high‑vibration applications, inspect the secondary ring annually for signs of wear or cracking. Replace if any hairline cracks are visible under magnification.
The SPYJ0000002036 2nd ring is manufactured under IATF 16949 and ISO 14001 certified systems. Each batch is 100% inspected for free diameter, gap width, thickness, and hardness (Rockwell C). Random samples are subjected to dynamic load testing (500,000 cycles at 5 kN axial force), corrosion testing (240h salt spray), and stress‑rupture testing (72 hours at 120°C under 6 kN load).
The ring meets DIN 471 (external retaining rings) and SINOTRUK Homan engineering standard Q/SQ 1012. A laser‑etched batch code on the flat face provides full traceability. Counterfeit rings often have inconsistent thickness, poor phosphate coating, or incorrect gap width. Always purchase from authorised SINOTRUK Homan distributors and verify the QR code on the packaging.
A fleet of 350 SINOTRUK T7H trucks in Brazil (severe vibrations from rough roads) experienced repeated gearbox gear retention failures with single‑ring designs. After retrofitting with the dual‑ring system including the SPYJ0000002036 secondary ring, zero ring‑related failures were reported over 2 years. The improved redundancy prevented axial movement even when the primary ring showed signs of wear.
Another user – a mining contractor in Indonesia – installed these secondary rings in PTO gearbox shafts on 200 HOWO dump trucks. After 18 months, the secondary rings showed no signs of wear or loosening, and no primary ring failures occurred. The phosphate coating resisted corrosion from tropical humidity and salt air, and the dual‑ring design provided peace of mind in critical driveline applications.
Each genuine SPYJ0000002036 2nd ring is packed in a sealed plastic bag inside a SINOTRUK Homan branded carton. The box includes a QR code and a hologram sticker. The ring itself has the OEM number laser‑etched on one flat face and is coated with a light protective oil. Secondary rings are often marked with a distinct groove or double dot to identify them as secondary.
Counterfeit rings often have a rough surface, missing etch, or a dull grey colour (genuine is dark grey/black with a consistent phosphate finish). The genuine ring feels smooth to the touch and snaps cleanly into the groove. Always scan the QR code before installation. Using a fake secondary ring can lead to gear disengagement, transmission damage, and void the vehicle warranty.
Summary: The SINOTRUK Homan 2nd Ring (OEM SPYJ0000002036) delivers redundant axial retention, high fatigue resistance, and easy installation for heavy‑duty gearboxes and drivelines. Ensure fail‑safe gear positioning – choose this genuine component trusted by fleets and mechanics worldwide.
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