Overview
The ZF 4657.066.021 6 WG 211 Powershift Transmission Assembly | Complete Unit is a fully integrated drop-in replacement for heavy-duty powershift drivelines. This complete assembly, identified by SKU 4657.066.021, serves as the central power distribution hub within the WG 211 series, managing torque flow from the engine through six forward speeds. It integrates the main housing, clutch packs, and hydraulic control circuits into a single sealed unit. For optimal hydraulic stability, this assembly works in concert with the 4657120005: PRESSURE REGULATOR, which modulates system pressure to prevent clutch slippage under load.
Symptoms of Failure
- Delayed or harsh engagement: When the complete unit wears, operators experience a pronounced lag between shifting and gear engagement, often accompanied by a jarring clunk. This is frequently linked to a failing 0501211384: VALVE that cannot maintain proper pilot pressure.
- Internal oil leaks and low line pressure: Worn sealing surfaces within the assembly cause transmission fluid to bypass internal circuits, leading to erratic shift quality and visible drips from the bell housing.
- Gear slipping under load: A worn 4656306145: PISTON within the clutch pack fails to apply sufficient clamping force, causing the transmission to lose torque transfer during uphill or heavy-load operations.
- Unusual whining or grinding noises: Debris from a degraded 0630532183: INDENTED RING can score planetary gears, producing a metallic grinding sound that intensifies with speed.
Technical Specifications
| Specification | Value |
|---|---|
| Overall Length | 720 mm |
| Dry Weight | 185 kg (408 lbs) |
| Housing Material | High-strength cast iron (GGG-40) |
| Input Torque Capacity | 1,200 Nm (885 lb-ft) |
| OEM Reference | ZF 4657.066.021 |
| Number of Speeds | 6 Forward / 1 Reverse |
| Hydraulic Fluid Type | ZF TE-ML 03 or Dexron III |
Compatibility
This complete unit is engineered for the WG 211 Series powershift family. It is directly compatible with ZF models WG180, WG200, and WG211 used in agricultural tractors, wheel loaders, and industrial forklifts. The assembly also fits select variants of the WG150 series with minor adapter modifications. Always verify the bell housing pattern and input shaft spline count (typically 14-tooth, 2-inch diameter) against your existing unit before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657120005 | PRESSURE REGULATOR | Maintains consistent hydraulic pressure to clutch packs |
| 0501211384 | VALVE | Controls pilot oil flow for shift timing |
| 0630532183 | INDENTED RING | Locks planetary gear carrier to prevent axial movement |
| 4656306145 | PISTON | Applies clamping force to clutch friction discs |
| 0732042767 | COMPRESSION SPRING | Returns piston to neutral position when de-energized |
| 0631612064 | SET SCREW | Secures valve body alignment during assembly |
| 0631610026 | SET SCREW | Locks pressure regulator adjustment nut |
| 4657101049 | TRANSMISSION HOUSING | Main structural casing for gear and shaft support |
| 4657301130 | HOUS.FRONT SECT | Front section housing the input shaft and pump drive |
| 4657301131 | HOUSING REAR PART | Rear section enclosing output shaft and PTO drive |
