Overview
The ZF 4644.131.409 FILLER NOZZLE is a precision-engineered fluid delivery component designed exclusively for the WG 201 Series transmission. This OEM genuine part, identified by SKU 4644.131.409, serves as the primary entry point for transmission fluid, directing oil from the external fill port into the main sump. Positioned on the upper housing assembly, it ensures a controlled flow rate during service intervals, preventing aeration and maintaining hydraulic circuit integrity. The nozzle integrates directly with the TRANSMISSION HOUSING and the TRANSMISSION HOUSING to create a sealed fill pathway, making it a critical component for routine maintenance and overhaul operations.
Symptoms of Failure
- Transmission fluid leaking from the fill tube area: A worn or cracked filler nozzle allows oil to escape around the housing interface, leaving visible puddles under the vehicle after parking.
- Hard shifting or delayed engagement during cold starts: When the nozzle deforms, it restricts oil flow, causing insufficient lubrication to the clutch packs and leading to sluggish gear engagement.
- Air ingestion into the hydraulic system: A damaged seal at the nozzle base draws air into the oil stream, producing foamy fluid and erratic shift patterns that worsen under load.
- Overheating transmission due to low fluid level: A slow leak from the filler nozzle gradually reduces sump volume, triggering thermal stress and potential slipping in the torque converter.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.131.409 |
| Material | Zinc-plated steel with nitrile sealing ring |
| Overall Length | 95 mm |
| Thread Size | M22 x 1.5 |
| Hex Size | 24 mm |
| Weight | 0.12 kg |
| OEM Reference | ZF 4644.131.409 |
| Operating Temperature Range | -40°C to +120°C |
Compatibility
This filler nozzle is engineered for the ZF WG 201 Series, including models WG180, WG200, WG210, and WG211. It also fits select variants of the WG150 and WG160 when used with the appropriate THREADED BUSH adapter. The part is not compatible with Ecomat or Ecolife series transmissions without housing modification. For a secure installation, always pair this nozzle with a new SCREW PLUG to prevent thread galling and ensure a leak-proof seal.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101160 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301323 | TRANSMISSION HOUSING | Secondary housing for valve body section |
| 4644301189 | THREADED BUSH | Reinforced insert for nozzle mounting |
| 4475280043 | SCREW PLUG | Seals unused fill port openings |
| 0634306198 | O-RING | Provides static seal between nozzle and housing |
| 0730365067 | TYPE PLATE | Identification tag for transmission model |
| 4644301161 | COVER PLATE | Protects internal components from debris |
| 0636100621 | HEXAGON SCREW | Fastener for housing assembly |
| 0631610020 | SET SCREW | Locks threaded bush in position |
| 0501218540 | BREATHER | Equalizes internal pressure during operation |
