Overview
The ZF 4646.004.037 4 WG 250(2) ERGOPOWER Transmission Assembly is a complete, factory-matched unit designed for heavy-duty commercial vehicles and off-highway machinery. This assembly serves as the central power transfer module within the WG 250 series, converting engine torque into controlled, multi-speed output for demanding applications. The SKU 4646.004.037 integrates the planetary gear sets, hydraulic control system, and output shaft into a single, pre-assembled package. For a full rebuild, this unit must be paired with a robust TRANSMISSION HOUSING (4646101028) to ensure proper alignment and oil containment. Additionally, the HOUSING (4646301095) provides critical structural support for the valve body, while the COVER (4646301087) seals the main case against contamination. Secure fastening is achieved using HEXAGON SCREW (0636015304) hardware, which must be torqued to factory specifications during installation.
Symptoms of Failure
When the ZF 4646.004.037 assembly begins to degrade, operators often notice specific performance issues. Delayed or harsh gear engagement is a primary indicator, frequently caused by worn clutch packs or valve body wear inside the unit. Another common failure is intermittent gear slipping under load, which manifests as a sudden loss of power during acceleration or climbing. External oil seepage from the main case seam often occurs when the assembly’s sealing surfaces fatigue, leading to low fluid levels and overheating. Finally, erratic shifting patterns or failure to shift into reverse can signal internal hydraulic pressure loss, a classic symptom of a failing ERGOPOWER assembly.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4646.004.037 |
| Series | WG 250 (2) ERGOPOWER |
| Assembly Type | Complete Transmission Unit |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Housing Material | High-Grade Cast Iron |
| Input Torque Capacity | 2,500 Nm (1,844 lb-ft) |
| OEM Reference | ZF 4 WG 250 |
| Bolt Torque (Main Case) | 120 Nm (88 lb-ft) |
Compatibility
This complete assembly is engineered for the ZF WG 250 series, but its core architecture shares components with other ERGOPOWER variants. It is directly compatible with the ZF WG 180, WG 200, and WG 250 models used in municipal trucks, refuse vehicles, and construction loaders. The unit also fits select ZF 4 WG 210 applications with minor adapter modifications. Always verify the bell housing pattern and output flange configuration against your existing transmission before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101028 | TRANSMISSION HOUSING | Main structural case for gear train |
| 4646301095 | HOUSING | Valve body support housing |
| 4646301087 | COVER | Seals main case opening |
| 0636015304 | HEXAGON SCREW | Fastener for housing assembly |
| 0636101828 | CAP SCREW | High-torque bolt for cover plate |
| 4646301102 | COVER SHEET | Thin sealing plate for oil passages |
| 4646301098 | COVER SHEET | Secondary sealing gasket |
| 0730365125 | TYPE PLATE | Identification label for serial number |
| 0631311009 | GROOVED STUD | Alignment pin for housing mating |
| 0636101193 | CAP SCREW | Fastener for valve body retention |
