Overview
The ZF 4644.156.002 POWER TAKE-OFF is a critical OEM genuine component engineered specifically for the WG 181 Series transmission. This unit interfaces directly with the transmission housing to transfer engine power to auxiliary hydraulic systems, such as pumps for dump bodies, winches, or refuse equipment. As a bolt-on assembly, it engages with the transmission’s internal gearing to provide a reliable mechanical output. The SKU 4644.156.002 is precision-machined to ZF’s exacting tolerances, ensuring seamless integration with the TRANSMISSION HOUSING and the HOUSING assembly. This part is designed for heavy-duty cycles, making it a cornerstone of power take-off systems in vocational trucks.
Symptoms of Failure
When the ZF 4644.156.002 POWER TAKE-OFF begins to wear, operators often notice distinct performance issues. Common failure symptoms include:
- Oil leaks around the PTO mounting flange – Worn seals or gaskets cause transmission fluid to seep, leading to low fluid levels and potential gear damage.
- Gear slipping under load – Internal wear or damaged teeth cause the PTO to disengage intermittently when driving hydraulic pumps, reducing operational efficiency.
- Unusual grinding or whining noises – Bearing failure or misalignment within the PTO assembly produces audible sounds during engagement or disengagement.
- Vibration at the PTO shaft – Imbalance or worn bushings transmit excessive vibration to the attached hydraulic equipment, accelerating component fatigue.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4644.156.002 |
| OEM Reference | ZF 4644.156.002 |
| Material | High-strength cast iron with hardened steel gears |
| Weight | Approx. 8.5 kg (18.7 lbs) |
| Dimensions (L x W x H) | 210 mm x 140 mm x 120 mm |
| Mounting Type | Flange-mounted, 6-bolt pattern |
| Torque Capacity | Up to 450 Nm (332 lb-ft) |
| Seal Type | Integrated lip seal with O-ring |
Compatibility
This OEM genuine part is primarily designed for the ZF WG 181 Series transmission. It is also compatible with the WG 180, WG 190, and WG 200 series models, provided the transmission housing configuration matches the mounting pattern. The 4644.156.002 POWER TAKE-OFF interfaces directly with the THREADED BUSH for secure alignment and the TYPE PLATE for identification. Always verify the transmission serial number and housing casting to ensure proper fitment before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Main structural casing for gear sets |
| 4644301380 | HOUSING | Secondary housing for PTO mounting |
| 4644301189 | THREADED BUSH | Alignment guide for PTO shaft |
| 0730365067 | TYPE PLATE | Identification tag for transmission model |
| 0631311009 | GROOVED STUD | Fastener for housing assembly |
| 4644301161 | COVER PLATE | Protective cover for PTO opening |
| 0636100621 | HEXAGON SCREW | Bolt for securing PTO flange |
| 0631610020 | SET SCREW | Adjustment screw for gear clearance |
| 0634801098 | SEALING RING | Prevents oil leakage at joints |
| 4644301117 | FIXING PLATE | Retains PTO in position |
