The BY612639000016 is a genuine Shacman Spherical Washer, a specialized component essential for ensuring perfect alignment and load distribution in pivotal suspension and steering joints. This precision-engineered washer, identified by part number BY612639000016, features a uniquely curved bearing surface designed to accommodate angular misalignment between bolted components. It plays a critical role in reducing stress concentration, preventing premature wear, and maintaining the integrity of your Shacman truck’s chassis and steering systems.
Unlike a standard flat washer, this spherical washer allows for a limited range of articulation while maintaining a consistent and secure clamping force. Manufactured from high-strength, hardened steel, the OEM part BY612639000016 is built to withstand extreme pressure and continuous vibration. Using this genuine component guarantees correct geometry, optimal performance of connected parts like tie-rod ends or leaf spring shackles, and contributes to safer vehicle handling and stability.
| Parameter | Specification | Details |
|---|---|---|
| OEM Part Number | BY612639000016 | Genuine Shacman Identification |
| Product Name | Spherical Washer | Curved bearing surface washer |
| Brand | Shacman | Original Equipment Manufacturer |
| Material | High-Carbon / Alloy Steel | Hardened and tempered for strength |
| Surface Treatment | Zinc Plated or Phosphate Coated | Corrosion and abrasion resistance |
| Washer Type | Spherical Seat Washer | Convex or concave curvature |
| Primary Function | Angular Compensation & Load Distribution | Allows articulation in bolted joints |
| Compatibility | Specific Shacman Chassis/Steering Points | Used in suspension linkages, shackles, etc. |
| SEO Description | Genuine Shacman Spherical Washer BY612639000016. OEM part for precise angular alignment, reducing wear in suspension and steering joints. Ensures durability and safety. | |
The Spherical Washer BY612639000016 solves a fundamental engineering challenge in truck chassis design: how to securely fasten components that must pivot or articulate. In applications like leaf spring shackles or tie-rod connections, the angles between parts change dynamically as the suspension moves or the wheels turn.
A standard flat washer would create a point load if the bolt isn’t perfectly perpendicular, leading to uneven pressure, bending, and rapid failure. The spherical washer’s curved surface allows the connected parts to find their natural angle while the bolt applies a clamping force normal (perpendicular) to the washer’s own surface, ensuring even load distribution.
Think of it as a ball-and-socket joint for a bolt. The spherical interface allows for multi-axis misalignment compensation. This eliminates bending moments on the bolt shank, prevents galling of the contact surfaces, and ensures that the full clamping force is used to secure the joint, not to fight against geometry.
Precision Ground Spherical Surface: The curvature of the BY612639000016 is manufactured to a precise radius with a smooth, hardened finish. This ensures consistent contact and low-friction articulation, preventing it from seizing or brinelling (forming indentations) under heavy load.
Uniform Load Distribution: By aligning the bolt force correctly, the washer spreads the clamping load over a wider area of the connected component. This prevents localized yielding, distortion of mounting ears, and fatigue cracking in critical chassis parts.
Reduced Stress on Fasteners: It protects the bolt from shear and bending stresses that would otherwise occur in a misaligned joint. This allows the bolt to perform its primary job of providing clamp force, dramatically increasing the overall reliability and safety of the connection.
Wear Compensation: In pivoting joints, slight wear is inevitable. The spherical interface of the BY612639000016 can accommodate minor wear in the joint components while maintaining a secure connection, extending the service interval before a complete joint rebuild is necessary.
Leaf Spring Shackles: This is a primary application. The shackle allows the spring to change length as it flexes. Spherical washers at the shackle bolt connections accommodate the arc of movement, preventing bind and keeping the spring functioning freely.
Steering Linkages (Tie-Rod Ends, Drag Links): While the ball joint itself provides movement, the mounting point at the steering arm or pitman arm may use a spherical washer to ensure the bolt is loaded purely in tension, not in bending, as the linkage moves through its range.
Stabilizer Bar Links: The links connecting the sway bar to the chassis or axle experience multi-directional movement. Spherical washers here ensure quiet operation and prevent link breakage by allowing the joint to articulate without side load on the bolt.
Cab or Engine Mounts: Some mounting systems use spherical washers to allow for slight settling or movement while maintaining a tight clamp, isolating vibration and preventing mount bracket failure.
Spherical washers are not interchangeable. They are part of a matched set, typically one convex and one concave. The BY612639000016 will be one of the pair. Installing it on the wrong side, or substituting a flat washer, defeats its purpose and can cause joint failure. Always replace in the original orientation.
Clean and Inspect: Before installing the new BY612639000016, thoroughly clean the mating spherical seat on the opposing component (e.g., the shackle plate). Inspect for cracks, pitting, or excessive wear. A damaged seat will ruin the new washer quickly.
Correct Assembly Sequence: Follow the manufacturer’s sequence: bolt, washer, component, mating washer (if applicable), nut. Ensure the spherical surfaces are mated together, not against a flat surface.
Proper Torque Specification: Torque the bolt to the specified value using a calibrated wrench. Overtorquing can flatten the spherical curvature or crack the hardened washer. Undertorquing allows movement that leads to impact wear and eventual failure of the joint.
Use of Thread Locking Compound: In many chassis applications, a medium-strength thread locker is applied to the bolt threads to prevent loosening from vibration. This is often more effective than over-tightening a nut against a spherical surface.
Excessive Play or Clunking: A worn or collapsed washer can create perceptible looseness in the joint, leading to audible clunks or bangs over bumps, especially in the suspension.
Uneven Tire Wear or Poor Steering Feel: In steering linkages, failed washers can allow slight but abnormal movement, causing toe angle changes that scrub tires or create a vague, imprecise steering response.
Visible Wear or Damage: During inspection, look for flattened, cracked, or deeply gouged washers. Severe cases may show elongation of the bolt hole in the connected component due to improper load bearing.
Bolt Failure: Repeated bending stress from a misaligned joint will eventually cause the bolt to fatigue and snap. A broken shackle or steering bolt is a catastrophic failure.
The exact radius, hardness, and material grade of the BY612639000016 are specified to work in harmony with the mating Shacman component. A generic “similar” spherical washer may have a different radius, leading to point contact and rapid wear.
It may also be made of softer material that deforms under load, losing its crucial geometric function. For a component that directly affects chassis alignment and safety, the genuine OEM part is a non-negotiable for reliable, long-term performance.
Spherical washers should be inspected during every major chassis service or suspension overhaul. If any play is detected in a joint that uses them, disassemble to inspect. Replacement is cheap insurance.
Always replace spherical washers as a matched pair and with a new bolt if the old one shows any necking (stretching) or thread damage. It is a best practice to replace these small components whenever the joint is disassembled for any service.
The BY612639000016 is typically made from medium to high-carbon steel (e.g., Grade 8 or similar) that is heat-treated to a specific hardness (often Rockwell C 38-45). This provides the ideal balance: hard enough to resist deformation, yet tough enough to resist brittle fracture.
The spherical surface is precision-ground after heat treatment to achieve a smooth finish and accurate geometry. The final plating provides corrosion resistance without adding a thick, soft layer that could affect the precise fit of the joint.
The Shacman Spherical Washer (OEM: BY612639000016) exemplifies how a simple, small component can have an outsized impact on vehicle safety, handling, and durability. It is the intelligent interface that allows rigid bolted connections to accommodate real-world movement.
Neglecting to use the correct, high-quality spherical washer is an invitation to premature wear, unsafe looseness, and potentially dangerous component failure. For chassis and steering joints that perform as designed, insist on the genuine Shacman BY612639000016.
