Overview
The ZF 4616.108.408 COUNTERSHAFT is a critical internal component engineered for the WG 65 series of heavy-duty transmissions. This OEM genuine part serves as the primary torque-transfer interface, synchronizing gear rotation within the main shaft assembly. Positioned parallel to the input and output shafts, the countershaft distributes engine power across multiple gear sets, ensuring smooth engagement under high-load conditions. The SKU 4616.108.408 is precision-machined to ZF’s original specifications, guaranteeing exact fitment and long-term durability in commercial vehicles, construction equipment, and marine applications.
Symptoms of Failure
- Gear grinding or hard shifting: A worn countershaft can cause misalignment between gear teeth, leading to audible grinding noises or difficulty engaging gears during operation.
- Vibration under load: Excessive play in the countershaft bearings or splines often results in noticeable driveline vibration, particularly when accelerating or climbing grades.
- Oil contamination with metal debris: As the countershaft surface wears, microscopic metal particles can enter the transmission fluid, visible during routine oil changes as glitter or sludge.
- Intermittent power loss: A failing countershaft may cause the transmission to slip out of gear momentarily, especially under heavy torque demands, reducing overall driveline efficiency.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4616.108.408 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Overall Length | 485 mm (estimated) |
| Diameter (bearing journals) | 45 mm / 55 mm |
| Weight | 8.7 kg (19.2 lbs) |
| Spline Count | 22 involute splines |
| OEM Reference | ZF 4616.108.408 |
| Heat Treatment | Carburized & quenched to HRC 58-62 |
Compatibility
This countershaft is specifically designed for the ZF WG 65 series transmission family. Based on its spline geometry and bearing spacing, it is also compatible with the following ZF models: WG180, WG200, and WG250 (all variants). It integrates directly with the 4616105402 OUTPUT shaft assembly and is secured within the 4616101119 TRANSMISSION HOUSING. During installation, the 4005303005 OUTPUT FLANGE is mounted to the output shaft, while the 0636011038 HEXAGON SCREW is used to fasten the countershaft bearing retainer. Always verify your transmission serial number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616105402 | OUTPUT | Transfers torque from countershaft to driveline |
| 4005303005 | OUTPUT FLANGE | Connects output shaft to universal joint |
| 4616101119 | TRANSMISSION HOUSING | Encloses and supports all internal gear sets |
| 0636011038 | HEXAGON SCREW | Secures countershaft bearing cap |
| 0636011118 | HEXAGON SCREW | Fastens output flange to shaft |
| 0636016015 | HEXAGON SCREW | Mounts housing to bell housing |
| 0631306085 | CYLINDRICAL PIN | Aligns countershaft bearing race |
| 0634313118 | O-RING | Seals countershaft bore against oil leaks |
| 0636304019 | SCREW PLUG | Closes oil gallery access port |
| 0634801152 | SEALING RING | Prevents fluid loss at countershaft exit |
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