Overview
The ZF 4644.351.015 AXLE is a precision-machined internal component engineered specifically for the WG 181 series of heavy-duty transmissions. This OEM genuine part functions as a critical load-bearing shaft within the planetary gear set, ensuring smooth torque transfer and alignment of rotating assemblies. As an integral element of the differential system, the 4644.351.015 axle directly interacts with the TRANSMISSION HOUSING (4644101217) and the TRANSMISSION HOUSING (4644301383) to maintain structural integrity under high-stress operating conditions. This SKU is manufactured to ZF’s original specifications, guaranteeing exact fitment and long service life in commercial vehicle applications.
Symptoms of Failure
- Axial play or excessive end float: When the 4644.351.015 axle wears, you may detect noticeable movement in the output shaft, leading to misalignment and premature bearing failure.
- Metallic grinding noises during gear engagement: A worn axle surface can cause irregular contact with planetary gears, producing a distinct grinding sound that intensifies under load.
- Oil contamination with metallic particles: As the axle surface degrades, fine metal shavings enter the lubrication system, often visible during routine oil changes or when inspecting the SCREW PLUG (4475280043).
- Intermittent gear slipping under torque: A fatigued axle can allow the gear train to momentarily lose engagement, causing sudden power loss during acceleration or hill climbing.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4644.351.015 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Weight | 2.85 kg (6.28 lbs) |
| Length | 245 mm |
| Outer Diameter | 42 mm |
| Surface Hardness | 58-62 HRC |
| OEM Reference | ZF 4644.351.015 |
Compatibility
This axle is designed for the ZF WG 181 transmission series, which includes models such as WG180, WG181, WG190, and WG200. It is also compatible with select variants of the ZF Ecolite and Ecomid ranges that share the same planetary carrier architecture. Always verify your transmission’s serial number against the OEM parts list before installation. For complete assembly, pair this axle with the THREADED BUSH (4644301189) to ensure proper preload and alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101217 | TRANSMISSION HOUSING | Encloses and supports the gear train assembly |
| 4644301383 | TRANSMISSION HOUSING | Secondary housing for auxiliary gear sets |
| 4644301189 | THREADED BUSH | Provides threaded interface for axle retention |
| 4475280043 | SCREW PLUG | Seals oil passages and inspection ports |
| 0634306198 | O-RING | Prevents fluid leaks at housing joints |
| 0634801098 | SEALING RING | Creates static seal between axle and housing |
| 0730365067 | TYPE PLATE | Identifies transmission model and serial number |
| 0631311009 | GROOVED STUD | Secures cover plates and brackets |
| 4644301161 | COVER PLATE | Protects internal components from debris |
| 0636100621 | HEXAGON SCREW | Fastens housing sections together |
