Overview
The ZF 4644.301.380 HOUSING is a critical structural component designed for the WG 180 and WG 200 series transmissions. This OEM genuine part serves as the primary enclosure for the hydraulic control unit and valve body assembly, ensuring precise alignment of internal components under high torque loads. Positioned between the main transmission casing and the rear cover, this housing channels transmission fluid to critical lubrication points while maintaining structural rigidity. The SKU 4644.301.380 is machined from high-strength cast iron to withstand thermal expansion and vibration fatigue in heavy-duty industrial applications.
Symptoms of Failure
- External transmission fluid seepage at the rear housing seam – When the housing gasket surface warps, oil leaks develop around the mating flange, often mistaken for a simple gasket failure.
- Erratic gear engagement under load – A cracked housing distorts valve body alignment, causing delayed or harsh shifting in WG 180 and WG 200 units during uphill hauling.
- Metallic debris in transmission pan – Internal housing fractures shed casting particles into the fluid circuit, accelerating wear on the TRANSMISSION HOUSING and pump assembly.
- Audible whining noise from the transmission center section – Worn bearing bores within the housing create play in the main shaft, producing a high-pitched sound at cruising speeds.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.301.380 |
| Material | EN-GJL-250 Gray Cast Iron |
| Overall Length | 412 mm |
| Overall Width | 298 mm |
| Height | 187 mm |
| Weight | 14.6 kg (32.2 lbs) |
| Bolt Hole Pattern | 12x M12 on 330 mm PCD |
| OEM Reference | ZF 4644.301.380 |
| Surface Finish | Ra 1.6 μm on mating faces |
Compatibility
This housing is engineered for the ZF WG 181 series and is directly interchangeable with WG 180 and WG 200 transmissions used in mobile cranes, concrete pumps, and mining trucks. It fits models with serial numbers starting from 2018 onward. For proper installation, ensure the THREADED BUSH is torqued to 85 Nm before mounting the housing. The TYPE PLATE must be transferred from the old housing to maintain identification. Secure the assembly using the GROOVED STUD at the 6 o’clock position to prevent rotation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Main casing for gear train |
| 4644301189 | THREADED BUSH | Alignment insert for housing bolts |
| 0730365067 | TYPE PLATE | Identification tag for transmission model |
| 0631311009 | GROOVED STUD | Anti-rotation fastener for housing |
| 4644301161 | COVER PLATE | Seals the housing access port |
| 0636100621 | HEXAGON SCREW | M10 bolt for cover plate |
| 0631610020 | SET SCREW | Locks the threaded bush in place |
| 0634801098 | SEALING RING | Prevents fluid bypass at joints |
| 4644301117 | FIXING PLATE | Retains the valve body within housing |
| 0636016039 | HEXAGON SCREW | M12 bolt for fixing plate |
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