Overview
The ZF 4644.121.127 OIL PIPE is a precision-engineered fluid conduit designed specifically for the WG 200 series transmission. This OEM genuine part ensures consistent lubrication and hydraulic pressure delivery to critical internal components, including the clutch packs and valve body. Positioned within the lower valve body assembly, this oil pipe directs transmission fluid under pressure to prevent overheating and component wear. The SKU 4644.121.127 is manufactured to ZF’s exacting tolerances, guaranteeing a leak-free seal and optimal flow rate. When paired with the 4644105414: DISCONNECTION and 4644303409: OUTPUT FLANGE, this oil pipe forms a critical part of the transmission’s hydraulic circuit, ensuring smooth gear engagement and reliable power transfer.
Symptoms of Failure
- Transmission fluid puddles under the vehicle: A cracked or corroded oil pipe often leads to visible ATF leaks near the bell housing or oil pan, especially after prolonged operation.
- Delayed or harsh gear engagement: Insufficient hydraulic pressure from a compromised oil pipe causes sluggish shifts or abrupt clunking when moving from Park to Drive.
- Overheating transmission with burnt fluid smell: Restricted oil flow due to internal debris or pipe deformation reduces cooling capacity, leading to thermal degradation of the fluid.
- Whining or humming noise during acceleration: A partially blocked oil pipe creates cavitation in the pump, producing audible high-pitched sounds that intensify under load.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4644.121.127 |
| Material | Seamless steel tube with zinc-nickel coating |
| Length | 215 mm (estimated) |
| Outer Diameter | 12 mm |
| Wall Thickness | 1.5 mm |
| Weight | 0.18 kg |
| OEM Reference | ZF 4644.121.127 |
| Thread Type | M10 x 1.5 (both ends) |
| Operating Pressure | Up to 18 bar |
| Temperature Range | -40°C to +150°C |
Compatibility
This oil pipe is engineered for the ZF WG 200 series transmissions, including the WG200, WG210, and WG180 variants. It is also compatible with select ZF Ecomat 4HP and 5HP models that share the same valve body architecture. The part integrates directly with the 4644101231: TRANSMISSION HOUSING and is secured using the 0636021083: HEXAGON SCREW. For proper installation, ensure the transmission is drained and the oil pan is removed to access the pipe routing channels.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105414 | DISCONNECTION | Hydraulic quick-connect for oil cooler lines |
| 4644303409 | OUTPUT FLANGE | Connects transmission output shaft to driveshaft |
| 0636021083 | HEXAGON SCREW | M10 bolt for securing oil pipe brackets |
| 4644101231 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301305 | HOUSING | Torque converter housing cover |
| 0730365067 | TYPE PLATE | Identification plate with transmission serial number |
| 0631311009 | GROOVED STUD | Alignment pin for valve body assembly |
| 4475280078 | ADAPTER | Oil filter adapter with O-ring seal |
| 4644106300 | SHIFT SYSTEM | Electronic shift module with solenoids |
| 4644306500 | COVER PLATE | Access cover for valve body inspection |
