Overview
The ZF 4644.131.417 FILLER NOZZLE is a critical fluid management component engineered specifically for the WG 201 series transmission. This OEM genuine part serves as the primary interface for introducing transmission fluid into the hydraulic system, ensuring precise oil delivery during service intervals. Positioned on the upper section of the transmission assembly, the filler nozzle integrates directly with the TRANSMISSION HOUSING (4644101160) to maintain a sealed fluid path. The SKU 4644.131.417 is manufactured to ZF’s exacting tolerances, preventing contamination ingress and maintaining optimal lubrication pressure across all operating conditions.
Symptoms of Failure
- Transmission fluid seepage around the filler neck: A worn filler nozzle often causes visible oil drips or wet spots near the top of the transmission housing, leading to low fluid levels and potential gear damage.
- Difficulty achieving proper fluid fill volume: When the nozzle’s internal sealing surface degrades, technicians may struggle to reach the correct oil level, resulting in erratic shifting or gear slipping during heavy loads.
- Contaminated fluid entering the system: A cracked or brittle filler nozzle allows dirt and moisture to bypass the seal, accelerating wear on internal components like the TRANSMISSION HOUSING (4644301323) and reducing overall transmission lifespan.
- Audible air suction noise during operation: A compromised nozzle can create a vacuum leak, producing a whistling sound as air enters the hydraulic circuit, often mistaken for pump cavitation.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4644.131.417 |
| Material | Reinforced Nylon / Aluminum Alloy |
| Length (approx.) | 85 mm |
| Thread Size | M22 x 1.5 |
| Weight | 0.12 kg |
| OEM Reference | ZF 4644.131.417 |
| Operating Temperature Range | -40°C to +120°C |
| Seal Type | Integrated O-Ring (compatible with 0634306198: O-RING) |
Compatibility
This filler nozzle is designed for the ZF WG 201 series transmissions, which include the WG180, WG200, and WG210 models commonly found in heavy-duty commercial vehicles and off-highway equipment. It also fits select WG 200 variants where the filler port is located on the upper housing. For proper installation, ensure the nozzle mates securely with the THREADED BUSH (4644301189) and is sealed using the SCREW PLUG (4475280043) to prevent leaks. Always verify your transmission’s serial number against ZF’s compatibility chart before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101160 | TRANSMISSION HOUSING | Main structural casing for gear assembly |
| 4644301323 | TRANSMISSION HOUSING | Alternative housing variant for WG series |
| 4644301189 | THREADED BUSH | Provides threaded interface for filler nozzle |
| 4475280043 | SCREW PLUG | Seals unused filler ports |
| 0634306198 | O-RING | Creates leak-proof seal at nozzle base |
| 0730365067 | TYPE PLATE | Identification label for transmission model |
| 4644301161 | COVER PLATE | Protects internal components from debris |
| 0636100621 | HEXAGON SCREW | Fastens housing and cover components |
| 0631610020 | SET SCREW | Secures threaded bush in position |
| 0501218540 | BREATHER | Equalizes pressure inside transmission |
