Overview
The ZF 4644.004.207 4 WG 180(500) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly integrates the core hydraulic and mechanical components of the WG 180 series, providing seamless power distribution under extreme loads. The SKU 4644.004.207 serves as the central power transfer module, positioned between the torque converter and the output driveline. When rebuilding or replacing a worn transmission, this complete unit eliminates the need for piecemeal assembly, ensuring precise alignment of internal clutches and planetary gears. For structural integrity, it is commonly paired with the 4644101208: TRANSMISSION HOUSING and the 4644301333: HOUSING, which enclose the rotating assemblies.
Symptoms of Failure
- Delayed engagement or gear slipping under load: When the 4644.004.207 assembly loses internal seal integrity, hydraulic pressure drops, causing hesitation when shifting from neutral to forward or reverse. Operators often notice the machine “creeping” or failing to hold gear on inclines.
- External oil leaks near the bell housing or output flange: Worn gaskets or cracked casings in this assembly allow transmission fluid to escape. Look for puddles of ATF or Dexron fluid after the vehicle has been parked overnight.
- Unusual grinding or whining noises during power shifts: Damaged clutch packs or worn bearings inside the 4644.004.207 produce metallic sounds that intensify as the transmission heats up. This often accompanies a burnt smell from overheated friction material.
- Erratic shift patterns or loss of power to the wheels: A failing valve body or stuck spool within the assembly can cause the transmission to “hunt” between gears or refuse to shift out of low range.
Technical Specifications
| Specification | Value |
|---|---|
| Assembly Weight | 185 kg (408 lbs) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 560 mm |
| Housing Material | Cast Aluminum Alloy (A356) |
| Max Input Torque | 500 Nm (369 lb-ft) |
| OEM Reference | ZF 4644.004.207 |
| Fluid Capacity | 12.5 liters (3.3 gallons) |
Compatibility
This complete unit is engineered for the ZF WG 180 series, specifically the 4 WG 180(500) variant. It is also compatible with the WG 200 series transmissions that share the same bolt pattern and input shaft spline count. Applications include telehandlers, wheel loaders, and industrial tractors from manufacturers such as Manitou, JCB, and Linde. For proper sealing during installation, use the 0636305019: SCREW PLUG and the 4644301247: THREADED BUSH to secure hydraulic ports. The 0634303485: O-RING and 0634306023: O-RING are critical for preventing fluid bypass at the adapter plate. Always verify the 0730365125: TYPE PLATE on your existing unit to confirm model year and revision level before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101208 | TRANSMISSION HOUSING | Encloses the main gear train and provides mounting points |
| 4644301333 | HOUSING | Rear cover for output shaft support |
| 0730365125 | TYPE PLATE | Identification tag with serial number and specs |
| 0631311009 | GROOVED STUD | Locating pin for housing alignment |
| 0636305019 | SCREW PLUG | Seals hydraulic test ports |
| 4644301247 | THREADED BUSH | Reinforces threaded connections in soft aluminum |
| 0634303485 | O-RING | Seals the adapter plate interface |
| 4644301257 | ADAPTER | Converts input flange to different PTO configurations |
| 0634306023 | O-RING | High-temperature seal for clutch feed circuits |
| 4644106231 | SHIFT SYSTEM | Electro-hydraulic valve body for gear selection |
