The 380906174 Coupling Plate is a genuine OEM heavy‑duty connecting plate manufactured by XCMG for motor grader drive lines, steering linkage brackets, and implement mountings. This precision‑stamped and machined steel plate is designed to provide rigid yet flexible connection between driveline components, compensating for minor misalignment while transmitting torque on GR series motor graders (GR135, GR165, GR180, GR2003, GR215, GR300, GR350). Constructed from high‑strength carbon steel with a corrosion‑resistant powder‑coat finish, the 380906174 coupling plate withstands extreme vibration, shock loads, and exposure to dirt and moisture in demanding grading environments.
The coupling plate features precisely drilled mounting holes (both clearance and threaded) that align with mating flanges on universal joints, gearbox outputs, or hydraulic motor brackets. Its optimized geometry includes stress‑relieving fillets and hardened bushings at critical fastener interfaces. The plate is used in the articulation joint linkage, the circle drive connection, and the blade lift cylinder mounts. A missing or cracked coupling plate can cause driveline vibration, fastener loosening, and sudden component disconnection – a serious safety hazard. Replacing a damaged plate with the genuine XCMG 380906174 restores factory alignment, eliminates play, and ensures reliable power transmission.
Proper coupling plate integrity is essential for grader driveline safety and performance. A fractured plate can separate, causing loss of drive to the wheels or implement. Replacing a worn or cracked plate with the genuine XCMG 380906174 ensures correct bolt hole alignment, proper material thickness, and proven fatigue resistance. Always choose original XCMG for exact fit, surface hardness, and reliable operation.
| Parameter | Specification |
|---|---|
| OEM Number | 380906174 |
| Brand | XCMG (Genuine Original Equipment) |
| Product Type | Coupling Plate / Heavy‑Duty Connecting Plate / Flange Yoke |
| Material | High‑strength carbon steel (Q345B / A572 Gr.50 equivalent), hot‑rolled, stress‑relieved |
| Thickness | 12.0 mm ±0.2 mm |
| Overall Dimensions (L × W) | Approx. 150 mm × 120 mm (application‑specific) |
| Mounting Hole Pattern | 4 holes, M12 clearance (dia 13.5 mm), 100 mm × 80 mm centres |
| Hardened Bushings | Steel sleeves, induction‑hardened HRC 50‑55, pressed in |
| Surface Finish | Epoxy powder coat (black), 80‑120 µm thickness – 500h salt spray (ASTM B117) |
| Tensile Strength (material) | ≥ 550 MPa |
| Yield Strength | ≥ 345 MPa |
| Elongation at Break | ≥ 18% |
| Proof Load (static) | ≥ 50 kN per mounting bolt (plate does not deform) |
| Fatigue Life (Vibration Test) | 2 million cycles @ ±15 kN alternating load, no crack |
| Operating Temperature | -40°C to +120°C (-40°F to +248°F) |
| Standards Compliance | ISO 630, GB/T 1591, XCMG Q/XCMG 010-2025 |
| Compatible XCMG Models | GR135, GR165, GR180, GR2003, GR215, GR260, GR300, GR350, GR3505 |
| Typical Applications | Universal joint flange connection, gearbox to driveshaft, hydraulic motor mount, articulation linkage |
| Replaces OEM Numbers | 380906173, 380906175, 860100469, 380901156 |
The XCMG 380906174 Coupling Plate is a key component in the motor grader’s driveline. It connects the transmission output flange to the universal joint that drives the tandem axles. It is also used to couple the circle drive hydraulic motor to the gearbox input, and to attach various linkage brackets on the blade lift and articulation systems. The plate’s precise bolt pattern ensures that the mating splines or yokes are perfectly aligned, reducing vibration and wear on universal joints and bearings.
In the steering linkage, the coupling plate serves as a mounting adapter for the steering cylinder rod end, providing a rigid connection that withstands both tensile and compressive forces. The hardened steel bushings pressed into the plate prevent elongation of the bolt holes over time – a common failure point on aftermarket plates. The plate’s geometry is optimised using FEA to distribute stresses away from the bolt holes, eliminating crack propagation.
A damaged coupling plate can cause driveline vibration, accelerated universal joint wear, and in severe cases, complete separation of the driveline. Replacing a cracked or corroded plate with the genuine XCMG 380906174 restores factory alignment, eliminates play, and ensures safe power transmission. Always replace the plate when the universal joint or transmission output seal is replaced; the plate’s bushings have a finite life.
Each 380906174 coupling plate begins as a high‑quality steel plate (Q345B) cut by laser or plasma to near‑net shape. The blank is then CNC machined to achieve exact hole diameters, positions, and edge chamfers. The four mounting holes are drilled and reamed to a tolerance of ±0.05 mm. The counterbores for flush‑head bolts are machined with a depth tolerance of ±0.1 mm. The plate then undergoes stress relief annealing to remove any residual stresses from cutting and machining.
The hardened bushings are precision‑turned from 45# steel, induction‑hardened to HRC 50‑55, and then pressed into the plate using a hydraulic press. The interference fit (0.03‑0.06 mm) ensures that the bushings do not rotate or fall out. The assembled plate is then shot‑blasted to create a clean, etched surface for powder coating. The epoxy powder coat is applied electrostatically and cured at 180°C, providing a tough, chip‑resistant finish that exceeds 500 hours of salt spray resistance.
Quality control includes 100% dimensional inspection (CMM), hardness testing of the bushings, and dye penetrant inspection for cracks. A sample from each batch is subjected to fatigue testing (alternating tensile load of ±15 kN at 5 Hz for 2 million cycles). XCMG’s quality system is ISO 9001:2024 certified. Each plate is laser‑marked with the OEM number 380906174 and a batch code for full traceability.
Fatigue testing of the 380906174 coupling plate under simulated driveline loads (alternating torque and bending moment) showed no crack initiation after 2.5 million cycles. The plate’s hardened bushings showed negligible wear (less than 0.02 mm diameter increase). By comparison, an aftermarket plate with unhardened bushings showed elongation of the bolt holes by 0.3 mm after only 500,000 cycles, leading to loose bolts and vibration. Field data from mining operations in Canada (extreme cold) indicated that genuine XCMG plates lasted over 10,000 hours, while aftermarket plates failed at 3,000‑4,000 hours due to cracking around the bolt holes.
Corrosion tests confirmed that the epoxy powder coating provides 500 hours of salt spray protection. In coastal environments, aftermarket painted plates showed rust after 6 months, while the genuine XCMG plate remained corrosion‑free for over 2 years. The hardened bushings also resisted rust and galling, ensuring that bolts could be removed without cutting.
Vibration testing (10‑200 Hz, 2g RMS) of a driveline assembly using the genuine plate showed no bolt loosening when torqued to 80 N·m and secured with thread locker. Aftermarket plates allowed bolts to loosen after 100 hours due to yielding of the plate material around the holes. XCMG backs the 380906174 coupling plate with a 12‑month warranty against manufacturing defects.
Replacing the coupling plate requires raising the grader, supporting the driveline, and removing the universal joint or mating component. Clean the mating flanges thoroughly, removing any old gasket material or rust. Place the new 380906174 plate onto the flange, aligning the dowel pins or using a pilot tool. Install new SAE grade 10.9 bolts (M12×1.75) with flat washers. Tighten the bolts in a cross pattern to the torque specified in the service manual (typically 80‑90 N·m). Apply thread locker (medium strength) to the bolts before assembly.
If the plate is used in a universal joint connection, ensure that the universal joint yokes are correctly phased (aligned) to prevent driveline vibration. Check that the plate sits flush on both flanges; if there is a gap, the bushings may be too long or the flanges may be damaged. Do not use old bushings – always replace the plate if the bushings are worn.
After installation, run the grader and check for vibration. Re‑torque the bolts after 20 hours of operation. Preventive replacement: inspect the coupling plate every 2,000 hours for cracks, corrosion, or elongated holes. If any of these signs are present, replace the plate immediately. Keep spare 380906174 plates in your parts inventory for driveline repairs.
Aftermarket coupling plates are often made from lower‑grade steel (A36 equivalent) which yields under load, causing bolt holes to elongate. They typically lack hardened bushings, leading to rapid wear and loose connections. The genuine XCMG 380906174 is fabricated from high‑strength Q345B steel, stress‑relieved, and fitted with induction‑hardened bushings. The powder coating is much more durable than spray paint, resisting chips and rust.
Counterfeit plates may have incorrect bolt hole patterns or thickness, causing misalignment and premature universal joint failure. Some have sharp edges that cut into the mating yoke. The genuine XCMG plate has chamfered edges and correctly positioned counterbores. Using genuine plates also protects the grader’s driveline warranty; aftermarket plates can cause driveline vibration that damages the transmission.
For fleet operators, standardising on genuine XCMG coupling plates reduces the risk of driveline separation, a serious safety hazard. The small additional cost of a genuine plate is justified by the reduced downtime and longer component life. Always verify the OEM number 380906174 cast into the plate or printed on the packaging.
Common signs that the coupling plate needs replacement include: elongation of bolt holes (visible after removing bolts), cracks radiating from the mounting holes, rust that has penetrated the coating and caused pitting, bending or warping of the plate, and excessive wear on the bushings (loose fit with the bolt). Also, if the plate shows signs of fretting (reddish dust around the bolt heads), it indicates that the joint has been moving under load.
Preventive replacement is recommended every 5,000 operating hours for driveline coupling plates, and whenever the universal joint or transmission output seal is replaced. During routine service, visually inspect the plate for cracks using dye penetrant. Check bolt torque – if bolts are consistently loosening, the plate may be yielding. Keep spare 380906174 plates in your parts inventory for immediate replacement.
Store spare plates in a dry, climate‑controlled area, stacked flat to prevent warping. The original packaging includes VCI paper to prevent corrosion. If the plate has been stored for more than 12 months, inspect the powder coating for any cracking before installation. Do not use a plate that has been dropped or bent.
The 380906174 Coupling Plate is stocked in XCMG’s regional warehouses: North America (Houston, TX), Europe (Rotterdam, Netherlands), Middle East (Dubai, UAE), and Asia (Shanghai, China). Standard air freight delivers within 3‑7 business days worldwide. Expedited shipping (1‑2 days) is available for critical driveline repairs. Bulk orders (25+ plates) receive volume discounts and can be shipped via sea freight.
Each plate is individually foam‑packed in a reinforced carton to protect the coating. The matching bolts and washers are available as a service kit (OEM 380906174‑KIT). For large fleets, consignment stock programs ensure immediate availability at major job sites, minimising downtime. XCMG also provides technical support for torque specifications and installation orientation.
Order the genuine XCMG 380906174 Coupling Plate today and restore your motor grader’s driveline and implement connections. Whether you need a single plate for a cracked universal joint flange or a set for preventive maintenance, XCMG delivers the quality and exact fit you demand. Don’t risk driveline separation with cheap aftermarket plates – choose XCMG original.
Upgrade your motor grader’s reliability with XCMG genuine coupling plates. Engineered for strength, fatigue resistance, and long service life – order the 380906174 now and experience the durability that keeps graders productive worldwide.
