Overview
The ZF 4646.108.014 COUNTERSHAFT is a precision-machined OEM sub-assembly engineered for the WG 250, WG 260, and WG 310 series of heavy-duty transmissions. This countershaft serves as the central rotating element that transfers torque from the input shaft to the output shaft through a series of gear meshes, directly influencing gear ratio selection and overall driveline efficiency. As a core component of the transmission’s layshaft assembly, the SKU 4646.108.014 must maintain exacting tolerances to prevent vibration and power loss. It is typically housed within the TRANSMISSION HOUSING and secured using the 螺栓 fasteners, while the TYPE PLATE identifies the specific assembly variant.
Symptoms of Failure
- Whining or grinding noise during gear engagement: Worn countershaft bearings or gear teeth produce a distinct metallic sound, especially under load, indicating the need for immediate replacement.
- Intermittent gear slipping or jumping out of gear: A damaged countershaft can cause misalignment, leading to erratic power delivery and unexpected disengagement during operation.
- Excessive vibration in the transmission housing: As the countershaft loses its balance, vibrations transmit through the HOUSING, often felt in the vehicle cab or chassis.
- Oil contamination with metallic debris: Flaking or spalling on the countershaft surface introduces fine metal particles into the lubricant, visible during routine oil changes.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4646.108.014 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Overall Length | ~485 mm |
| Journal Diameter | ~55 mm (main bearing journals) |
| Weight | ~8.2 kg |
| Heat Treatment | Carburized & tempered to HRC 58-62 |
| OEM Reference | ZF 4646.108.014 |
| Surface Finish | Ground & polished (Ra ≤ 0.4 µm) |
Compatibility
This countershaft is designed for use in the following ZF transmission series: WG 258, WG 260, WG 261, WG 308, WG 310, and WG 311. It is also compatible with earlier WG 180 and WG 200 variants when used in conjunction with the correct ADAPTER PLATE and GASKET sets. Always verify the transmission serial number against the TYPE PLATE before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101162 | TRANSMISSION HOUSING | Encloses and supports all internal gear train components |
| 4646301334 | HOUSING | Secondary casing for auxiliary gear sets |
| 0636115293 | 螺栓 | High-strength bolt for countershaft bearing retention |
| 0730365125 | TYPE PLATE | Identification plate with transmission model and serial number |
| 4646201003 | POT | Oil collection pot for lubrication circuit |
| 4646106024 | SHIFT SYSTEM | Mechanical or pneumatic shift actuator assembly |
| 4646306071 | GASKET | Seal between housing and adapter plate |
| 4646306072 | ADAPTER PLATE | Mounting interface for transmission to engine bellhousing |
| 4646306073 | GASKET | Secondary seal for adapter plate interface |
| 0636102065 | CAP SCREW | Fastener for securing shift system components |
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