Overview
The ZF 4657.036.004 6 WG 191 Powershift Transmission Assembly | Complete Unit is a fully integrated drop-in replacement for heavy-duty powershift systems. This complete assembly houses the core planetary gear sets, clutch packs, and hydraulic control circuits required for smooth, high-torque shifting in off-highway machinery. As a complete unit, it eliminates the need for piecemeal rebuilding, ensuring immediate operational readiness. The SKU 4657.036.004 is the direct OEM reference for this specific WG 191 configuration, designed to bolt directly into the drivetrain without modification. It interfaces with the 4657101049: TRANSMISSION HOUSING to form the main structural shell, while the 4657301130: HOUS.FRONT SECT and 4657301131: HOUSING REAR PART enclose the rotating components.
Symptoms of Failure
- Delayed or harsh engagement: When the complete unit wears, internal clutch pack clearance increases, causing a noticeable lag or jarring shift when moving from neutral to forward or reverse.
- Intermittent gear slipping under load: Worn seals or scored drums within the assembly allow hydraulic pressure to bleed off, resulting in the transmission slipping out of gear when climbing grades or moving heavy loads.
- External oil seepage at housing joints: Fatigue in the main casing or gasket failure leads to fluid weeping around the mating surfaces of the housing sections, often visible as drips near the bell housing.
- Unusual whining or grinding noises: Bearing wear or planetary gear damage inside the complete unit produces a high-pitched whine or metallic grinding that intensifies with engine RPM.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4657.036.004 |
| Assembly Type | Complete Powershift Unit |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Primary Material | High-grade cast iron housing with hardened steel gears |
| Clutch Count | 6 (forward/reverse) |
| Max Input Torque | 1,200 Nm |
| Mounting Interface | SAE 3 bell housing pattern |
Compatibility
This complete unit is engineered for the ZF WG 191 series, but its architecture shares core dimensions with the broader WG family. It is directly compatible with ZF WG180 and WG200 transmissions that utilize the same six-speed powershift layout. The assembly is commonly found in telehandlers, wheel loaders, and agricultural tractors from manufacturers like Manitou, JCB, and Claas. For proper installation, ensure the 0631306816: CYLINDRICAL PIN is aligned correctly to index the housing sections during assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101049 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657301130 | HOUS.FRONT SECT | Front section enclosing input shaft |
| 4657301131 | HOUSING REAR PART | Rear section supporting output bearings |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing assembly |
| 0636102489 | CAP SCREW | Fastener for housing joint |
| 4656301148 | FIXING PLATE | Locks clutch piston in place |
| 0636102463 | CAP SCREW | Mounting bolt for valve body |
| 4657201133 | SCREEN SHEET | Filter mesh for hydraulic fluid |
| 0636115287 | CAP SCREW | High-tensile fastener for clutch pack |
| 4657301065 | PLATE | Thrust washer for planetary gear |
