Overview
The ZF 4644.131.205 FILLER NOZZLE is a precision-engineered fluid delivery component designed specifically for the WG 200 series transmission. This OEM genuine part, identified by SKU 4644.131.205, serves as the primary interface for introducing transmission fluid into the hydraulic system. Mounted directly onto the TRANSMISSION HOUSING, this nozzle ensures a controlled, splash-free fill process that prevents aeration of the oil. By directing fluid flow precisely, it maintains the correct oil level and pressure within the valve body, directly supporting the VALVE BLOCK and shift systems. Without this nozzle, the transmission cannot achieve proper lubrication or cooling during operation.
Symptoms of Failure
When the ZF 4644.131.205 filler nozzle degrades, operators often notice specific performance issues. Look for these failure indicators:
- External oil seepage at the fill point: A cracked or warped nozzle allows fluid to escape, leaving puddles under the vehicle. This is a common “ZF transmission oil leak at filler neck” issue.
- Erratic gear engagement or slipping: If the nozzle fails to seal correctly, air enters the hydraulic circuit, causing “transmission slipping after fluid change” symptoms.
- Difficulty filling or overfilling: A blocked or deformed nozzle restricts flow, leading to “hard to fill ZF transmission” complaints and inaccurate fluid levels.
- Whining pump noise: Aerated oil from a faulty nozzle creates cavitation, resulting in a high-pitched whine during acceleration.
Technical Specifications
| Specification | Value |
|---|---|
| OEM Part Number | 4644.131.205 |
| Material | Die-cast aluminum with corrosion-resistant coating |
| Overall Length | 95 mm |
| Inlet Diameter | 22 mm |
| Mounting Thread | M18 x 1.5 |
| Weight | 0.12 kg |
| Seal Type | Integrated O-ring groove |
| Operating Temperature Range | -40°C to +120°C |
Compatibility
This filler nozzle is engineered for the ZF WG series, with primary application in the WG 200 transmission family. It is also compatible with the WG 180 series and select WG 150 variants that share the same housing architecture. The part interfaces directly with the HOUSING assembly and is secured using a GROOVED STUD. For proper identification, always cross-reference the TYPE PLATE on your transmission to confirm model year and revision level before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101165 | TRANSMISSION HOUSING | Main structural casing that supports all internal components |
| 4644301304 | HOUSING | Secondary housing for valve body and shift mechanisms |
| 0730365067 | TYPE PLATE | Identification tag with transmission serial and model data |
| 0631311009 | GROOVED STUD | Fastener for securing filler nozzle to housing |
| 4644106300 | SHIFT SYSTEM | Mechanical assembly for gear selection |
| 4644306500 | COVER PLATE | Protective cover for transmission access points |
| 4644159300 | SHIFT SYSTEM | Alternate shift system variant for WG200 |
| 4644306560 | VALVE BLOCK | Hydraulic control unit for clutch and band actuation |
| 4644306408 | WASHER | Sealing washer for fluid connections |
| 4644107015 | SPEEDOMETER | Output speed sensor drive assembly |
