Overview
The ZF 4651.004.013 4 WG 100(500) Powershift Transmission Assembly | Complete Unit is a fully assembled, drop-in replacement designed for heavy-duty off-highway applications. This complete unit integrates the clutch packs, planetary gear sets, and hydraulic control system into a single, pre-tested assembly. As a core component of the WG 100 Series, it manages torque distribution across four forward and reverse speeds, ensuring smooth power delivery under extreme loads. The SKU 4651.004.013 is directly interchangeable with OEM ZF assemblies, eliminating the need for partial rebuilds. When installing this unit, ensure the TRANSMISSION HOUSING is free of cracks and that the O-RING seals are replaced to prevent fluid bypass.
Symptoms of Failure
- Delayed engagement or gear slipping under load: Worn clutch discs or degraded seals inside the assembly cause the transmission to hesitate before engaging forward or reverse, particularly when moving heavy equipment uphill.
- Erratic shift patterns and harsh shifting: Internal hydraulic pressure loss from a failing HOUSING or valve body leads to jarring gear changes and unexpected neutral drops.
- Contaminated transmission fluid with metallic debris: Bearing or gear wear within the assembly generates fine metal particles, turning the oil a gray or silver color and reducing lubrication efficiency.
- External oil leaks near the bell housing: Cracks in the HOUSING or degraded gaskets allow fluid to escape, often visible as drips after extended operation.
Technical Specifications
| Parameter | Value |
|---|---|
| Assembly Weight | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | Cast aluminum alloy (A356) |
| OEM Reference | ZF 4651.004.013 / 4 WG 100(500) |
| Max Input Torque | 500 Nm (369 lb-ft) |
| Fluid Capacity | 12.5 liters (3.3 gallons) |
Compatibility
This complete unit is engineered for the ZF WG 100 Series powershift transmissions, specifically the 4 WG 100(500) variant. It is also compatible with the WG 180, WG 200, and WG 250 models used in telehandlers, wheel loaders, and agricultural tractors. For partial rebuilds, the SCREEN SHEET and SCREEN SHEET filters must be cleaned or replaced to maintain hydraulic integrity.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4651101007 | TRANSMISSION HOUSING | Encloses gear train and supports bearing loads |
| 4651301029 | HOUSING | Hydraulic valve body housing for clutch control |
| 0634303928 | O-RING | Seals fluid passages between housing sections |
| 4651301024 | HOUSING | Rear housing for output shaft support |
| 4651203002 | SCREEN SHEET | Fine mesh filter for hydraulic oil |
| 4651303005 | SCREEN SHEET | Coarse mesh pre-filter for sump |
| 0636101032 | CAP SCREW | Secures housing flanges with M10 thread |
| 0630361028 | SEALING CAP | Closes unused hydraulic ports |
| 4475280060 | SCREW PLUG | Drain or fill plug for oil pan |
| 0634303312 | O-RING | Seals screw plug against leakage |
