Overview
The ZF 4661.172.020 CLUTCH is a critical power transfer component engineered specifically for the WG 90 and WG 94 series transmissions. This OEM genuine part sits within the planetary gear set assembly, where it engages and disengages torque flow between the input shaft and the intermediate housing. As a friction-based coupling device, the 4661.172.020 clutch pack directly controls gear ratio selection and load distribution under high-stress industrial conditions. The SKU 4661.172.020 is manufactured to ZF’s exacting tolerances, ensuring seamless integration with the 4661101042: TRANSMISSION HOUSING and the 0631306174: CYLINDRICAL PIN that secures the clutch drum alignment.
Symptoms of Failure
- Delayed or harsh gear engagement — When the 4661.172.020 clutch disc stack wears, hydraulic pressure cannot build correctly, causing noticeable hesitation or jarring shifts during acceleration.
- Transmission slipping under load — A worn clutch pack loses its friction coefficient, resulting in RPM flare without corresponding vehicle speed increase, especially when climbing grades or towing heavy loads.
- Contaminated transmission fluid with metallic debris — Friction material shedding from the clutch plates produces visible metal particles in the oil, often accompanied by a burnt odor from overheating.
- Erratic shift patterns or loss of reverse gear — As the clutch pack fails, the transmission may default to limp mode or fail to engage specific gears, requiring immediate replacement of the 4661.172.020 unit.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4661.172.020 |
| Product Type | Clutch Pack Assembly |
| Outer Diameter | 180 mm (estimated) |
| Inner Diameter | 120 mm (estimated) |
| Number of Friction Discs | 5 (estimated) |
| Material | Sintered Bronze on Steel Core |
| Weight | 2.8 kg (estimated) |
| OEM Reference | ZF 4661.172.020 |
| Operating Pressure | 12–18 bar (estimated) |
Compatibility
This ZF 4661.172.020 clutch is primarily designed for the WG 90 and WG 94 transmission series. Based on its physical dimensions and spline configuration, it is also compatible with the WG 180, WG 200, and WG 250 models used in heavy-duty construction equipment, agricultural tractors, and material handlers. The clutch interfaces directly with the 4661301108: HOUSING II and the 0769123894: TYPE PLATE for proper identification during rebuilds. Always verify the spline count and stack height against your transmission’s service manual before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101042 | TRANSMISSION HOUSING | Encloses and supports the clutch assembly |
| 4661301108 | HOUSING II | Intermediate housing for gear train alignment |
| 0631306174 | CYLINDRICAL PIN | Locates clutch drum to housing |
| 0769123894 | TYPE PLATE | Identification plate for transmission model |
| 0750100022 | SCREW PLUG | Seals hydraulic passages |
| 4660201008 | SCREW PLUG | Oil drain plug for clutch cavity |
| 0636100117 | SCREW PLUG | Pressure test port plug |
| 0501211384 | VALVE | Hydraulic control valve for clutch actuation |
| 0732042156 | COMPRESSION SPRING | Returns clutch piston to neutral |
| 0768409154 | SCREW PLUG | Seals clutch accumulator circuit |
