Overview
The ZF 0631.306.064 CYLINDRICAL PIN is a precision-engineered locating and alignment component used within the planetary gearset and differential housing assemblies of ZF’s heavy-duty WG-series transmissions. This OEM genuine part (SKU: 0631.306.064) functions as a critical dowel or pivot pin, ensuring exact positioning of internal components such as the differential carrier and clutch pack retainers. By maintaining tight tolerances, it prevents axial movement and rotational misalignment that can lead to premature wear on surrounding hardware. This pin is typically installed alongside the 5838109021: DIFFERENTIAL and the 0750117075: TAPER ROLLER BEARING to secure the differential assembly within the housing.
Symptoms of Failure
- Erratic gear engagement and slipping under load: A worn or sheared cylindrical pin allows the differential carrier to shift, causing intermittent power loss and “clunking” noises during acceleration.
- Internal metallic debris in transmission fluid: As the pin degrades, it sheds fine steel particles that contaminate the oil, often visible during drain intervals as glitter or sludge.
- Oil seepage from the differential housing gasket: Misalignment from a failed pin distorts the housing seal surface, leading to chronic leaks around the output flange.
- Vibration at highway speeds (40-60 mph): Loss of pin integrity permits the 2095209019: DIFFERENTIAL to wobble, transmitting harmonic vibrations through the driveline.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 0631.306.064 |
| Type | Cylindrical Pin (Dowel Pin) |
| Material | Case-hardened alloy steel (DIN 1.3505 equivalent) |
| Diameter | 12 mm (nominal) |
| Length | 45 mm |
| Surface Hardness | 58-62 HRC |
| Weight | Approx. 0.04 kg (40 g) |
| OEM Reference | ZF 0631.306.064 |
| Compatible Fastener | 0631329086: SPRING PIN (retaining pin) |
Compatibility
This cylindrical pin is engineered for ZF WG-series transmissions, specifically the WG100, WG130, and WG131 models. It is also commonly found in the differential carrier assemblies of WG180 and WG200 variants. The pin interfaces directly with the 5838300817: THRUST WASHER and the 5838300682: DIFFERENTIAL AXLE to maintain proper end-play. For applications using the WG200, verify that the 5838300811: THRUST WASHER and 5841302064: THRUST WASHER are also inspected during rebuild.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 5838109021 | DIFFERENTIAL | Distributes torque to axle shafts |
| 0750117075 | TAPER ROLLER BEARING | Supports differential carrier rotation |
| 2095209019 | DIFFERENTIAL | Secondary differential unit for multi-axle |
| 0631329086 | SPRING PIN | Retains cylindrical pin in bore |
| 5838300817 | THRUST WASHER | Controls axial clearance of differential |
| 5838300682 | DIFFERENTIAL AXLE | Carries side gears and pinion shaft |
| 5838300811 | THRUST WASHER | Reduces friction on differential side gear |
| 5841302064 | THRUST WASHER | Spacer for planetary gearset |
| 5838300812 | SEALING RING | Prevents oil leakage at differential hub |
| 5838300137 | OUTER CLUTCH DISK | Friction element for clutch pack |
