Overview
The ZF 4657.026.117 6 WG 190 Powershift Transmission Assembly | Complete Unit is a fully assembled, drop-in replacement for heavy-duty powershift applications. This complete unit integrates the main gear cluster, clutch packs, and hydraulic control system within a single robust housing. As the core of the WG 190 series, it manages torque distribution across six forward speeds, ensuring smooth power delivery under high load. The SKU 4657.026.117 is a direct OEM-spec assembly, designed to restore original performance without the need for partial rebuilds. It interfaces directly with the TRANSMISSION HOUSING and the HOUS.FRONT SECT to form the sealed driveline envelope.
Symptoms of Failure
- Delayed or harsh gear engagement: When the internal clutch packs or valve body wear, operators experience a noticeable lag or a jarring shift between forward and reverse, especially under load.
- Progressive oil leaks at housing seams: Cracks or warpage in the main casing allow transmission fluid to seep past the gasket lines, often pooling near the bell housing or rear output flange.
- Intermittent gear slipping under torque: A worn assembly fails to maintain hydraulic pressure, causing the transmission to momentarily lose drive power during uphill climbs or heavy hauling.
- Unusual whining or grinding noises: Bearing wear or gear tooth damage within the complete unit produces a metallic sound that increases with engine RPM, indicating imminent internal failure.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 4657.026.117 |
| Assembly Type | Complete Powershift Unit (6 WG 190) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 720 mm |
| Overall Width | 510 mm |
| Overall Height | 480 mm |
| Housing Material | High-Grade Cast Iron (GGG-40) |
| Max Input Torque | 1,900 Nm |
| Fluid Capacity | 22 liters (with cooler circuit) |
| Related Fastener | CAP SCREW (M12 x 1.5) |
| Related Fastener | CAP SCREW (M14 x 1.5) |
Compatibility
This complete unit is engineered for the WG 190 Series powershift family. It is a direct fit for ZF models including the WG180, WG190, and WG200 transmissions used in construction loaders, forklifts, and agricultural tractors. The assembly also shares mounting interfaces with the HOUSING REAR PART and the HOUSING REAR SECTION, making it suitable for both standard and extended-length chassis configurations. Always verify your transmission serial number against the 4657 prefix to confirm compatibility.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101082 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657201166 | HOUS.FRONT SECT | Front section housing for input shaft |
| 4657201170 | HOUSING REAR PART | Rear casing for output flange support |
| 4657298102 | HOUSING REAR SECTION | Extended rear section for PTO adapter |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing mating |
| 0636100801 | CAP SCREW | M12 fastener for housing bolts |
| 0636100803 | CAP SCREW | M14 fastener for bell housing |
| 4656301148 | FIXING PLATE | Locks bearing preload in rear section |
| 4657301032 | SCREEN SHEET | Fine mesh filter for oil sump |
| 4657301033 | SCREEN SHEET | Coarse mesh pre-filter for pump intake |
