Overview
The ZF 4644.151.091 COUPLING is a critical torque-transfer component engineered specifically for the WG 180 and WG 200 transmission series. This OEM genuine part sits between the engine flywheel and the transmission input shaft, acting as a flexible connector that dampens torsional vibrations while ensuring precise power delivery. The SKU 4644.151.091 is manufactured to ZF’s exacting tolerances, guaranteeing a direct fit and long service life in heavy-duty industrial applications. When paired with a robust TRANSMISSION HOUSING (4644101164), this coupling maintains driveline alignment and reduces stress on adjacent gearsets.
Symptoms of Failure
- Torque converter shudder during acceleration: A worn 4644.151.091 coupling causes noticeable vibration or jerking when the transmission shifts under load, often misdiagnosed as a slipping clutch.
- Metallic rattling from the bell housing: As the coupling’s elastomeric element degrades, loose metal components create a distinct rattle at idle or low RPM, indicating imminent failure.
- Fluid contamination with rubber debris: Internal degradation of the coupling can shed particles into the transmission fluid, leading to clogged filters and erratic shifting behavior.
- Hard shifting between forward and reverse: A failing coupling disrupts hydraulic pressure modulation, resulting in delayed or harsh engagement when changing direction.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4644.151.091 |
| Outer Diameter | 180 mm (estimated) |
| Inner Bore Diameter | 45 mm (estimated) |
| Material | High-tensile steel hub with nitrile rubber element |
| Weight | 2.4 kg (estimated) |
| OEM Reference | ZF 4644.151.091 |
| Torque Capacity | 1,200 Nm (estimated) |
Compatibility
This coupling is designed for the ZF WG 180 and WG 200 series transmissions, commonly found in municipal buses, fire trucks, and heavy construction equipment. It directly replaces the original coupling in WG 180-6, WG 200-6, and WG 200-8 models. For proper installation, ensure the mating TRANSMISSION HOUSING (4644301371) is free of cracks and the TYPE PLATE (0730365067) is legible for model verification. The coupling also requires correct torque on the GROOVED STUD (0631311009) to prevent loosening during operation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101164 | TRANSMISSION HOUSING | Encloses and supports gear train assembly |
| 4644301371 | TRANSMISSION HOUSING | Alternate housing variant for WG 200 |
| 0730365067 | TYPE PLATE | Identifies transmission model and serial number |
| 0631311009 | GROOVED STUD | Secures coupling to flywheel with precise torque |
| 4644303060 | COVER PLATE | Seals access port for coupling inspection |
| 4644201011 | COVER PLATE | Protective plate for rear housing opening |
| 4644201010 | COVER PLATE | Lower housing cover for oil pan access |
| 4644301372 | COVER PLATE | Side cover for valve body service |
| 0636610028 | STUD | Mounting stud for transmission bell housing |
| 0634306525 | O-RING | Seals coupling hub to prevent fluid leaks |
