Overview
The ZF 4646.131.039 FILLER NOZZLE is a precision-engineered OEM sub-assembly designed for the WG 250, WG 260, and WG 310 series transmissions. This component serves as the primary fluid entry point, directing transmission oil from the filler tube directly into the main sump cavity. Positioned at the upper interface of the TRANSMISSION HOUSING, the nozzle ensures a controlled, splash-free fill that prevents aeration and maintains proper hydraulic pressure during service. The SKU 4646.131.039 is a direct replacement for the original factory unit, guaranteeing a seamless fit and reliable sealing against the HOUSING assembly.
Symptoms of Failure
- External oil seepage at the filler neck: A worn or cracked filler nozzle often causes slow drips or wet spots around the top of the transmission, leading to low fluid levels and potential overheating.
- Difficult or slow fluid filling: When the internal bore becomes distorted or blocked by debris, you may experience backflow or excessive time required to reach the correct oil level.
- Gear engagement hesitation after refill: A failing nozzle can introduce air into the hydraulic circuit, resulting in soft shifts or delayed clutch pack engagement immediately following a fluid change.
- Contaminated fluid from loose debris: A degraded plastic or metal nozzle can shed particles into the sump, accelerating wear on the COVER and valve body components.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4646.131.039 |
| Material | Reinforced Nylon / Aluminum Alloy |
| Overall Length | 85 mm |
| Inlet Diameter | 22 mm |
| Mounting Thread | M12 x 1.5 |
| Weight | 0.12 kg |
| Sealing Type | Integrated O-Ring (NBR) |
| Operating Temperature Range | -40°C to +120°C |
| OEM Reference | ZF 4646.131.039 |
Compatibility
This filler nozzle is specifically engineered for the ZF WG series of powershift transmissions. It is a direct fit for the WG 250, WG 260, and WG 310 series. It also retrofits to earlier WG 180 and WG 200 models when used with the appropriate HEXAGON SCREW kit. Always verify your transmission serial number against the housing casting to ensure compatibility with the TRANSMISSION HOUSING bore.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101112 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4646301316 | HOUSING | Secondary housing for valve body |
| 4646301283 | COVER | Seals the upper transmission cavity |
| 0636015304 | HEXAGON SCREW | Fastener for nozzle mounting |
| 0636101828 | CAP SCREW | High-torque fastener for housing |
| 4646201022 | COVER SHEET | Protective plate for internal access |
| 4646301295 | SCREEN SHEET | Filter mesh for oil return circuit |
| 0730365190 | TYPE PLATE | Identification tag for transmission |
| 0631311009 | GROOVED STUD | Alignment pin for housing assembly |
| 0636101193 | CAP SCREW | Low-profile fastener for cover |
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