Overview
The ZF 4651.004.022 4 WG 100(500) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway machinery. This assembly integrates the clutch pack, planetary gear sets, and hydraulic control valves into a single, pre-assembled module. It serves as the core power transfer component within the WG 100 series transmission, converting engine torque into controlled, shiftable output. The SKU 4651.004.022 is a direct replacement for original equipment, ensuring precise fitment and hydraulic flow. When installed, it works in conjunction with the 4651101007 TRANSMISSION HOUSING to form the sealed main case, while the 4651301029 HOUSING supports the rear output section.
Symptoms of Failure
- Erratic shifting or gear slippage under load: Worn clutch discs or damaged seals inside the assembly cause the transmission to slip between forward and reverse gears, especially during heavy excavation or grading operations.
- Hydraulic oil contamination with metallic debris: Internal bearing or gear wear generates fine metal particles in the transmission fluid, often visible during oil changes or filter inspections.
- Delayed engagement when shifting from neutral to drive: A failing valve body or worn piston seals result in a 2-3 second lag before the transmission engages, reducing operator control precision.
- External oil leaks near the bell housing or output flange: Degraded 0634303928 O-RING seals or cracked housing interfaces allow fluid to escape, leading to low pressure and eventual transmission failure.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4651.004.022 |
| Assembly Type | Complete Powershift Unit (4 WG 100/500) |
| Weight (approx.) | 185 kg (408 lbs) |
| Housing Material | Cast Iron (GGG-40) |
| Overall Length | 620 mm |
| Max Input Torque | 500 Nm (369 ft-lbs) |
| Fluid Capacity (internal) | 4.5 liters |
| Seal Type | Viton O-Rings (multiple) |
Compatibility
This assembly is specifically engineered for the ZF WG 100 series transmissions, including models WG 100, WG 100/500, and WG 100/600. It is also compatible with select WG 180 and WG 200 variants that share the same 4-speed planetary architecture and hydraulic control interface. Always verify the transmission serial number against the OEM parts list before ordering. For related sealing and mounting components, the 4651301024 HOUSING is used in later WG 200 builds, while the 0634303928 O-RING is a common replacement across all WG series units.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4651101007 | TRANSMISSION HOUSING | Main case for gear and shaft support |
| 4651301029 | HOUSING | Rear output housing for PTO mounting |
| 0634303928 | O-RING | Seals housing joints against fluid leaks |
| 4651301024 | HOUSING | Intermediate housing for clutch pack |
| 4651203002 | SCREEN SHEET | Filters debris from hydraulic circuit |
| 4651303005 | SCREEN SHEET | Secondary filtration for oil return line |
| 0636101032 | CAP SCREW | Fastens housing sections together |
| 0630361028 | SEALING CAP | Closes unused hydraulic ports |
| 4475280060 | SCREW PLUG | Seals drain and fill holes |
| 0634303312 | O-RING | Seals cap screw and plug interfaces |
