Overview
The ZF 4657.026.129 6 WG 190 Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly integrates the main gear cluster, clutch packs, and hydraulic control components into a single, ready-to-install package. As the core of the WG 190 series, it replaces the entire rotating assembly and valve body section, eliminating the need for piecemeal rebuilds. The SKU 4657.026.129 is a direct OEM reference for ZF’s 6-speed powershift architecture, ensuring precise gear engagement under load. When installing this unit, always verify the integrity of the 4657101082: TRANSMISSION HOUSING and the 4657201166: HOUS.FRONT SECT to guarantee proper alignment and sealing.
Symptoms of Failure
- Delayed or harsh engagement – When the assembly’s internal clutches wear, operators experience a noticeable lag or jarring shift when moving from neutral to forward or reverse. This is a common long-tail search query for “ZF WG 190 shifting delay.”
- Loss of power under load – A failing 4657.026.129 unit will cause the machine to bog down or slip during heavy pushing or grading, often accompanied by rising transmission oil temperature.
- Erratic gear hunting – Worn valve body components within the assembly lead to the transmission jumping between gears or failing to hold a selected ratio, especially on inclines.
- External oil seepage – Cracks in the assembly’s mating surfaces or degraded seals allow hydraulic fluid to weep from the bell housing area, leaving visible puddles after shutdown.
Technical Specifications
| Specification | Value |
|---|---|
| OEM Part Number | 4657.026.129 |
| Assembly Type | 6 WG 190 Powershift (Complete Unit) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Housing Material | High-grade cast iron (GGG-40) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Clutch Count | 6 hydraulic (wet multi-disc) |
| Max Input Torque | 1,900 Nm |
| OEM Reference | ZF 4657.026.129 |
Compatibility
This complete assembly is engineered for the ZF WG 190 series, which includes the WG 190, WG 190 II, and WG 190 III variants. It is also mechanically compatible with the WG 180 and WG 200 series when used with the correct 4657201170: HOUSING REAR PART and 4657298102: HOUSING REAR SECTION. Applications include telehandlers, wheel loaders, and dump trucks from manufacturers such as Liebherr, JCB, and Caterpillar that utilize ZF drivelines. Always cross-reference your existing transmission tag to confirm the 4657.026.129 suffix matches your unit’s build code.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101082 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657201166 | HOUS.FRONT SECT | Front section housing input shaft and pump drive |
| 4657201170 | HOUSING REAR PART | Rear casing for output shaft and PTO mount |
| 4657298102 | HOUSING REAR SECTION | Extended rear housing for longer wheelbase machines |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing mating surfaces |
| 0636100801 | CAP SCREW | M12 bolt for housing flange fastening |
| 4656301148 | FIXING PLATE | Locking plate for clutch pack retention |
| 4657301032 | SCREEN SHEET | Fine mesh filter for hydraulic circuit (short) |
| 4657301033 | SCREEN SHEET | Fine mesh filter for hydraulic circuit (long) |
| 0636100803 | CAP SCREW | M10 bolt for valve body attachment |
