Overview
The ZF 4657.066.304 6 WG 211 Powershift Transmission Assembly | Complete Unit is a fully integrated, factory-built gearbox core designed for heavy-duty off-highway machinery. This complete assembly serves as the central power distribution hub, converting engine torque into controlled, multi-speed output for loaders, graders, and industrial vehicles. The SKU 4657.066.304 denotes a direct replacement unit that includes all internal clutch packs, shafts, and valve bodies pre-assembled within the main casing. It sits between the torque converter and the final drive, managing gear selection under full load without interrupting power flow. For a robust rebuild, this assembly must be paired with a new TRANSMISSION HOUSING to ensure proper alignment and sealing of the main bore.
Symptoms of Failure
- Erratic gear engagement under load: When the internal clutch packs or planetary gears wear, the transmission may hesitate or slam into gear, especially when shifting from forward to reverse.
- Torque converter shudder at low RPM: A failing assembly often causes vibration during inching operations, indicating worn stator or turbine components inside the unit.
- External oil seepage from the bell housing: Cracks in the main casing or degraded gaskets lead to hydraulic fluid leaks, visible as drips around the mating surfaces.
- Delayed or no reverse engagement: Internal seal failure within the clutch piston circuits can cause a complete loss of reverse gear, requiring immediate replacement of the complete assembly.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 4657.066.304 |
| Series | WG 211 |
| Assembly Type | Complete Powershift Unit |
| Estimated Weight | 185 kg (408 lbs) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Primary Material | Cast Iron Housing with Steel Gears |
| OEM Reference | ZF 4657.066.304 |
| Bolt Torque Spec (Housing) | 120 Nm (M12 fasteners) |
Compatibility
This complete unit is engineered for the ZF WG 211 series of powershift transmissions. It is directly compatible with the following ZF models and their variants: WG 180, WG 200, WG 211, and WG 250. These transmissions are commonly found in articulated dump trucks, wheel loaders, and telescopic handlers from manufacturers such as Volvo, Case, and JCB. When installing, ensure the HOUS.FRONT SECT and the HOUSING REAR PART are free from scoring to guarantee a proper fit. Additionally, always replace the CYLINDRICAL PIN during assembly to maintain dowel alignment between the sections.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101087 | TRANSMISSION HOUSING | Main structural casing for gear and shaft support |
| 4657301172 | HOUS.FRONT SECT | Front section housing for input shaft and pump drive |
| 4657301173 | HOUSING REAR PART | Rear section enclosing output shaft and parking brake |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing section mating |
| 0636102489 | CAP SCREW | Fastener for housing-to-bell housing joint |
| 4656301148 | FIXING PLATE | Retaining plate for clutch piston assembly |
| 0636102463 | CAP SCREW | Bolt for fixing plate and valve body attachment |
| 4657201133 | SCREEN SHEET | Fine mesh filter for hydraulic oil circuit |
| 0636115287 | CAP SCREW | High-strength bolt for clutch pack retention |
| 4657301065 | PLATE | Thrust washer plate for planetary gear set |
