Overview
The ZF 4657.035.002 5 WG 191 Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway machinery. This assembly integrates the main gear cluster, clutch packs, and hydraulic control elements into a single, ready-to-install package. As the core power transfer module for the WG 191 series, it replaces worn-out internal components without the need for piecemeal rebuilding. The SKU 4657.035.002 is precision-balanced to OEM tolerances, ensuring seamless engagement across all five forward speeds. This assembly sits directly between the 4657101049: TRANSMISSION HOUSING and the 4657301130: HOUS.FRONT SECT, forming the structural backbone of the drivetrain.
Symptoms of Failure
- Delayed or harsh gear engagement: When the internal clutch discs or seals wear, operators experience a noticeable lag or a jarring shift between forward and reverse gears.
- Erratic power delivery under load: A failing assembly causes the machine to surge or lose torque during grading or dozing operations, often accompanied by a whining noise from the planetary set.
- Hydraulic fluid contamination: Worn friction material from the assembly sheds debris into the oil, leading to clogged filters and a burnt smell from the transmission breather.
- Intermittent neutral condition: The transmission may suddenly drop out of gear at low speeds, requiring the operator to cycle the shift lever to regain drive.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 4657.035.002 |
| Series | WG 191 |
| Overall Length | 620 mm (24.4 in) |
| Dry Weight | 185 kg (408 lbs) |
| Housing Material | High-grade cast iron (GGG-40) |
| Clutch Type | Wet multi-disc, spring-applied |
| Max Input Torque | 1,200 Nm (885 lb-ft) |
| Speed Count | 5 forward / 1 reverse |
| OEM Reference | ZF 1320 301 002 |
Compatibility
This complete unit is engineered for the ZF WG 191 transmission family, which includes the WG180, WG190, WG191, and WG200 variants used in wheel loaders, telehandlers, and industrial tractors. It directly replaces the internal rotating assembly in models with serial numbers beginning with 4657. The assembly mates with the 4657301131: HOUSING REAR PART and is secured using 0631306816: CYLINDRICAL PIN for precise alignment. For complete installation, verify that your machine uses a 5-speed powershift configuration with a 10-spline input shaft.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101049 | TRANSMISSION HOUSING | Encloses and supports the main gear assembly |
| 4657301130 | HOUS.FRONT SECT | Front section housing the input shaft and pump drive |
| 4657301131 | HOUSING REAR PART | Rear section containing the output flange and PTO mount |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing mating surfaces |
| 0636102489 | CAP SCREW | M12 bolt for securing the front housing |
| 4656301148 | FIXING PLATE | Locks the output shaft bearing in position |
| 0636102463 | CAP SCREW | M10 bolt for the fixing plate |
| 4657201133 | SCREEN SHEET | Fine mesh filter for the lube oil circuit |
| 0636115287 | CAP SCREW | M8 bolt for the screen sheet cover |
| 4657301065 | PLATE | Clutch piston retaining plate |
