Overview
The ZF 4661.002.019 4 WG 90 Powershift Transmission Assembly represents a complete, drop-in replacement unit engineered for heavy-duty off-highway machinery. As the core rotating assembly within the WG 90 series, this unit integrates the planetary gear sets, clutch packs, and hydraulic control elements required for seamless power delivery under extreme loads. The SKU 4661.002.019 designates a fully assembled transmission, not a subcomponent, making it a critical upgrade for equipment experiencing total gear train failure. This assembly mounts directly to the 4661101021: TRANSMISSION HOUSING and is secured by the 0631306174: CYLINDRICAL PIN for precise alignment, while the 4661301047: HOUSING II encloses the rear clutch section.
Symptoms of Failure
- Erratic gear engagement or slipping under load: Worn clutch discs or damaged planetary gears inside the 4661.002.019 cause delayed shifts or complete loss of drive torque, especially during directional changes.
- Metallic grinding noise from the transmission bell housing: Bearing failure or gear tooth spalling within the assembly produces a distinct, high-pitched whine or grinding sound that intensifies with engine RPM.
- Hydraulic oil contamination with bronze or steel particles: Internal wear of the clutch packs or thrust washers sheds metallic debris into the oil, visible during routine fluid changes as glitter-like particles.
- Transmission overheating without external leaks: Slipping clutches generate excessive heat, causing the oil temperature to spike rapidly even when the cooler circuit is functioning properly.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 4661.002.019 |
| Assembly Type | Complete Powershift Unit (4 WG 90) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | Cast Iron (GGG-40) |
| Clutch Disc Material | Sintered Bronze on Steel |
| Max Input Torque | 900 Nm |
| Oil Capacity (assembly) | 12.5 Liters |
| OEM Reference | ZF 4 WG 90 |
Compatibility
This complete unit is specifically designed for the ZF WG 90 series of powershift transmissions. It is a direct fit for models including the WG 90, WG 100, and WG 120, which are commonly found in telescopic handlers, wheel loaders, and agricultural tractors from manufacturers such as JCB, Manitou, and Claas. The assembly also shares core dimensions with the WG 180 and WG 200 series, though hydraulic valve body configurations may differ. Always verify the bell housing pattern against your existing TRANSMISSION HOUSING before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101021 | TRANSMISSION HOUSING | Main structural casing for the gear train |
| 4661301047 | HOUSING II | Rear section enclosing clutch pack C |
| 4661301093 | TUBE | Hydraulic oil feed tube for clutch lubrication |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for housing-to-assembly fit |
| 0769123894 | TYPE PLATE | Identification tag with serial number |
| 0750100022 | SCREW PLUG | Magnetic drain plug for oil sump |
| 0636302602 | SCREW PLUG | Hexagonal fill plug with sealing washer |
| 0634100633 | O-RING | Seal for hydraulic pressure ports |
| 4661301041 | NOZZLE | Oil jet for planetary gear lubrication |
| 4661301062 | NOZZLE | Secondary oil jet for clutch cooling |
