Overview
This ZF 4657.171.021 COUPLING is a critical OEM genuine component engineered for the WG 190 and WG 210 transmission series. Situated between the torque converter and the main gear train, this coupling serves as the primary mechanical link that transmits rotational force while dampening torsional vibrations. The SKU 4657.171.021 is precision-machined to ZF’s exacting tolerances, ensuring seamless power transfer and alignment within the driveline assembly. When installed alongside the 4657101034: TRANSMISSION HOUSING, this coupling maintains the structural integrity required for heavy-duty industrial applications.
Symptoms of Failure
- Transmission shudder during acceleration: A worn coupling causes uneven power delivery, resulting in noticeable vibration or jerking when the vehicle moves from a standstill.
- Delayed engagement or gear slipping: As the coupling loses its friction surface integrity, operators may experience hesitation before the transmission engages, or the unit may slip out of gear under load.
- Metallic grinding noises from the bell housing: Degraded coupling teeth or splines produce a distinct grinding sound, particularly during gear changes or when the transmission is under heavy torque.
- Oil contamination with metal particles: Internal wear of the coupling releases fine metallic debris into the transmission fluid, often visible during routine oil changes or filter inspections.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4657.171.021 |
| Material | High-strength alloy steel with hardened splines |
| Outer Diameter | 210 mm (estimated) |
| Inner Diameter | 85 mm (estimated) |
| Overall Length | 95 mm (estimated) |
| Weight | 3.2 kg (estimated) |
| OEM Reference | ZF 4657.171.021 |
| Torque Capacity | Up to 2,500 Nm (estimated) |
Compatibility
This coupling is specifically designed for the ZF WG 210 series, with confirmed compatibility across the WG 190, WG 180, and WG 200 transmission models. It directly interfaces with the 4657201027: HOUS.FRONT SECT and the 4657201012: HOUSING REAR PART, forming a complete assembly that ensures proper alignment and oil flow. The coupling is also used in certain ZF off-highway and marine transmission variants that share the WG platform architecture.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101034 | TRANSMISSION HOUSING | Encloses and supports the entire gear train assembly |
| 4657201027 | HOUS.FRONT SECT | Front section housing that aligns the input shaft and coupling |
| 4657201012 | HOUSING REAR PART | Rear housing section that supports output shaft bearings |
| 0631306792 | CYLINDRICAL PIN | Precision alignment pin for housing doweling |
| 0636100801 | CAP SCREW | Fastener for securing housing sections |
| 4656301148 | FIXING PLATE | Locks coupling in position within the housing |
| 4657301032 | SCREEN SHEET | Fine mesh filter for oil circuit protection |
| 4657301033 | SCREEN SHEET | Secondary oil filter screen for high-pressure circuits |
| 0636100803 | CAP SCREW | Heavy-duty bolt for coupling retention |
| 4681301040 | OIL FEED.HOUSG. | Distributes lubrication to coupling and bearings |
Frequently Asked Questions
Q: How do I know if the 4657.171.021 coupling needs replacement?
A: Primary indicators include persistent transmission shudder during low-speed acceleration, metallic debris in the oil pan, and a noticeable delay when shifting from neutral to drive. A visual inspection of the coupling splines for wear is recommended during any major transmission overhaul.
Q: Can this coupling be used in a WG 180 transmission?
A: Yes, the 4657.171.021 coupling is fully compatible with WG 180, WG 190, and WG 200 models. However, always verify the spline count and overall length against your specific transmission serial number to ensure a correct fit.
Q: What other parts should I replace at the same time?
A: It is strongly advised to replace the 0631306792: CYLINDRICAL PIN and both 4657301032 and 4657301033 screen sheets simultaneously, as these components experience correlated wear and contamination during coupling failure.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
Request a Quote →
