Overview
The ZF 4644.238.002 TUBE for WG201 is a precision-engineered fluid conduit designed to maintain proper hydraulic pressure and lubrication flow within the transmission assembly. This OEM genuine part sits within the valve body circuit, directing transmission fluid to critical clutch packs and planetary gear sets. The SKU 4644.238.002 is manufactured to ZF’s exacting tolerances, ensuring seamless integration with the TRANSMISSION HOUSING (4644101172) and TRANSMISSION HOUSING (4644301390). Without this tube, the WG201 series cannot achieve the required hydraulic circuit integrity for smooth gear engagement.
Symptoms of Failure
- External oil seepage around the tube connection points – A worn or cracked 4644.238.002 tube often causes visible fluid drips near the transmission pan or bell housing, leading to low fluid levels and eventual overheating.
- Delayed or harsh gear engagement – When the tube fails to deliver consistent hydraulic pressure, operators experience hesitation when shifting from neutral to drive or reverse, especially under load.
- Erratic shift timing and slipping – A compromised tube disrupts the precise oil flow required for clutch application, resulting in RPM flare during acceleration or unexpected downshifts.
- Transmission overheating warnings – Insufficient lubrication due to tube blockage or leakage forces the system to run hotter, triggering dashboard alerts or thermal shutdown in severe cases.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.238.002 |
| Product Type | Hydraulic Tube / Fluid Conduit |
| Material | Steel with corrosion-resistant coating |
| Length (approx.) | 185 mm |
| Outer Diameter | 12 mm |
| Wall Thickness | 1.5 mm |
| Weight | 0.12 kg |
| OEM Reference | ZF 4644.238.002 |
| Sealing Components | 0634306198: O-RING, 0634801098: SEALING RING |
| Mounting Hardware | 0636100621: HEXAGON SCREW, 0636302005: SCREW PLUG |
Compatibility
This tube is specifically engineered for the ZF WG201 series transmissions. Based on its design and hydraulic routing, the 4644.238.002 is also compatible with the WG180 and WG200 series models that share the same valve body architecture. It integrates directly with the THREADED BUSH (4644301189) and SCREW PLUG (0636302005) to create a leak-proof seal. For retrofitting into older WG series units, verify that the transmission housing casting matches the tube’s mounting flange geometry.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101172 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301390 | TRANSMISSION HOUSING | Secondary housing section for valve body |
| 4644301189 | THREADED BUSH | Provides threaded anchor for tube fasteners |
| 0636302005 | SCREW PLUG | Seals hydraulic ports in the housing |
| 0634306198 | O-RING | Prevents fluid leaks at tube joints |
| 0634801098 | SEALING RING | Ensures metal-to-metal seal integrity |
| 0730365067 | TYPE PLATE | Identification plate for transmission model |
| 0631311009 | GROOVED STUD | Alignment pin for housing assembly |
| 4644301161 | COVER PLATE | Protects valve body from debris |
| 0636100621 | HEXAGON SCREW | Secures tube and housing components |
