Overview
The ZF 4644.301.226 TRANSMISSION HOUSING is a critical structural component designed specifically for the WG180 and WG200 series transmissions. This OEM genuine part serves as the primary casing that encloses the gear train, valve body, and hydraulic circuits, ensuring precise alignment of internal components under high torque loads. As the central backbone of the assembly, the housing (SKU: 4644.301.226) must withstand extreme thermal expansion and mechanical stress. When rebuilding a WG180 or WG200 unit, this housing is often replaced alongside the 4644105413 DISCONNECTION mechanism and the 4642303093 OUTPUT FLANGE to restore factory tolerances.
Symptoms of Failure
- Persistent oil seepage at mating surfaces: A cracked or warped housing allows transmission fluid to escape around the bellhousing or pan rail, leading to low fluid levels and eventual gear slipping.
- Abnormal gear engagement noise: When the housing distorts, bearing bores lose concentricity, causing a distinct whining or grinding sound during shifts in WG200 series units.
- Recurring bolt loosening: A fatigued housing can no longer maintain clamping force on the 0636021010 HEXAGON SCREW fasteners, resulting in vibration and misalignment of the 4644101222 TRANSMISSION HOUSING assembly.
- Contaminated fluid from casting porosity: Micro-fractures in the housing allow debris ingress, accelerating wear on clutches and seals.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.301.226 |
| Material | High-grade aluminum alloy (A356-T6) |
| Weight | 14.2 kg (31.3 lbs) |
| Overall Length | 485 mm |
| Overall Width | 320 mm |
| Overall Height | 275 mm |
| OEM Reference | ZF 4644.301.226 |
| Bolt Hole Pattern | 12-point, M12 x 1.5 |
| Max Operating Temperature | 120°C (248°F) |
Compatibility
This transmission housing is engineered for the ZF WG180 and WG200 series, including all sub-variants such as WG180-1, WG180-2, WG200-1, and WG200-2. It directly replaces the earlier 4644101222 housing in later production runs. The casting accommodates the 0730365067 TYPE PLATE mounting boss and the 0631311009 GROOVED STUD locations. For full assembly, pair this housing with the 4644301298 COVER PLATE and 0634306525 O-RING to seal the access port. The 0636305026 SCREW PLUG and 4475280078 ADAPTER are also required for hydraulic circuit completion.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105413 | DISCONNECTION | Clutch pack separation mechanism |
| 4642303093 | OUTPUT FLANGE | Driveshaft connection interface |
| 0636021010 | HEXAGON SCREW | Housing fastening bolt |
| 4644101222 | TRANSMISSION HOUSING | Earlier housing variant |
| 0730365067 | TYPE PLATE | Identification label |
| 0631311009 | GROOVED STUD | Alignment dowel |
| 4644301298 | COVER PLATE | Access port cover |
| 0634306525 | O-RING | Sealing gasket |
| 0636305026 | SCREW PLUG | Drain/fill port plug |
| 4475280078 | ADAPTER | Hydraulic line fitting |
Authorized ZF Distributor
We are a certified supplier of genuine ZF components.
