Overview
The ZF 4646.302.128 HELICAL GEAR is a critical power transmission component engineered specifically for the WG series of industrial transmissions. This OEM genuine part, identified by SKU 4646.302.128, sits within the gear train assembly, where it meshes with adjacent shafts to transfer torque smoothly and quietly. Its helical tooth design reduces noise and vibration compared to spur gears, ensuring consistent performance under heavy loads. As a direct replacement for worn units, this gear maintains the precise gear ratio required for optimal drivetrain efficiency in ZF WG250 through WG311 series applications.
Symptoms of Failure
- Whining or grinding noise during operation: When the 4646.302.128 helical gear wears, tooth surface pitting or chipping produces a distinct high-pitched whine or grinding sound, especially under load or during deceleration.
- Vibration and shuddering in the driveline: Uneven wear on the gear teeth causes irregular engagement, leading to noticeable vibration felt through the chassis or transmission housing during acceleration.
- Oil contamination with metallic debris: As the gear degrades, small metal particles shed into the transmission fluid, visible as glitter or sludge during oil changes, indicating internal gear damage.
- Intermittent gear slipping or loss of power: Advanced wear reduces tooth contact area, causing momentary slipping under torque, particularly when shifting between forward and reverse.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4646.302.128 |
| Type | Helical Gear |
| Material | Case-Hardened Alloy Steel (20MnCr5 equivalent) |
| Module | 4.5 mm (estimated) |
| Number of Teeth | 28 (estimated) |
| Helix Angle | 15° (estimated) |
| Outer Diameter | 135 mm (estimated) |
| Bore Diameter | 40 mm (estimated) |
| Face Width | 45 mm (estimated) |
| Weight | 2.8 kg (estimated) |
| OEM Reference | ZF 4646.302.128 |
Compatibility
This helical gear is designed for use in ZF WG series transmissions, including the WG180, WG200, WG250, WG251, WG258, WG260, WG261, WG308, and WG311 models. It is commonly found in off-highway vehicles, construction equipment, and industrial machinery where the WG260 series is prevalent. Always verify the gear count and shaft fitment against your specific transmission serial number before installation.
During replacement, inspect the TRANSMISSION HOUSING (4646101028) for cracks or wear, as a damaged housing can misalign the gear. The HOUSING (4646301095) and COVER (4646301087) should also be checked for proper sealing. Secure the assembly using a HEXAGON SCREW (0636015304) to ensure correct torque retention.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101028 | TRANSMISSION HOUSING | Encloses and supports gear assembly |
| 4646301095 | HOUSING | Secondary housing for bearing support |
| 4646301087 | COVER | Seals the gear chamber |
| 0636015304 | HEXAGON SCREW | Fastens housing components |
| 0636101828 | CAP SCREW | Secures cover plates |
| 4646301102 | COVER SHEET | Thin protective cover |
| 4646301098 | COVER SHEET | Alternate cover sheet variant |
| 0730365125 | TYPE PLATE | Identification label |
| 0631311009 | GROOVED STUD | Alignment dowel for assembly |
| 0636101193 | CAP SCREW | Fastener for gear retention |
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