Overview
The ZF 4644.311.161 PUMP FLANGE is a critical interface component engineered for the WG180 and WG200 series transmissions. This OEM genuine part, identified by SKU 4644.311.161, serves as the mounting point and hydraulic seal between the transmission pump and the main housing assembly. It ensures precise alignment of the pump drive gear while maintaining oil pressure integrity within the hydraulic circuit. The flange is precision-machined to mate directly with the 4644101208: TRANSMISSION HOUSING, forming a leak-proof connection that supports consistent lubrication and clutch actuation. Without this component, the pump cannot deliver the required flow to the shift system or torque converter.
Symptoms of Failure
- Hydraulic oil leaks at the pump-to-housing interface: Worn sealing surfaces or cracks in the flange cause visible oil seepage, often mistaken for a failing pump gasket.
- Erratic gear engagement or delayed shifting: A warped or damaged flange disrupts pump pressure, leading to soft shifts or hesitation when moving from neutral to drive.
- Whining or cavitation noise from the transmission pump: Misalignment from a degraded flange allows air ingestion, producing a high-pitched whine under load.
- Overheating transmission fluid: Insufficient pump flow due to flange distortion reduces cooling circulation, causing elevated sump temperatures.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.311.161 |
| Material | High-grade cast iron with corrosion-resistant coating |
| Weight | Approx. 1.8 kg (4.0 lbs) |
| Outer Diameter | 165 mm |
| Bolt Hole Pattern | 6x M10 on 140 mm PCD |
| OEM Reference | ZF 4644.311.161 |
| Sealing Surface Finish | Ra 0.8 µm |
Compatibility
This pump flange is specifically designed for the ZF WG180 and WG200 series transmissions. It is a direct fit for all WG180 variants (including WG180A, WG180B) and WG200 models (WG200C, WG200D) used in off-highway trucks, wheel loaders, and agricultural machinery. The flange also interfaces with the 4644301333: HOUSING and secures the 0730365125: TYPE PLATE for identification. For proper installation, ensure the 0631311009: GROOVED STUD is torqued to factory specifications.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101208 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301333 | HOUSING | Intermediate support for pump assembly |
| 0730365125 | TYPE PLATE | Identification tag for transmission model |
| 0631311009 | GROOVED STUD | Fastener for flange alignment |
| 0636305019 | SCREW PLUG | Seals hydraulic test ports |
| 4644301247 | THREADED BUSH | Reinforces bolt threads in housing |
| 0634303485 | O-RING | Primary seal between flange and pump |
| 4644301257 | ADAPTER | Converts pump outlet to cooler lines |
| 0634306023 | O-RING | Secondary seal for adapter connection |
| 4644106231 | SHIFT SYSTEM | Controls clutch pack engagement |
