Overview
The ZF 0636.020.165 HEXAGON SCREW is a critical fastening component engineered for the WG100, WG130, and WG131 transmission series. This OEM genuine part secures internal housing assemblies within the gearbox, ensuring precise alignment under high-torque conditions. As a hexagon-headed fastener, it provides superior grip during installation and resists vibrational loosening. The SKU 0636.020.165 is specifically designed to mate with the 4143101009 HOUSING and the 4143301025 HOUSING, forming a leak-proof seal when combined with the 0634313603 O-RING.
Symptoms of Failure
- Transmission fluid seepage at bolt heads: A worn or stripped hexagon screw allows oil to bypass the sealing surface, causing visible drips under the bell housing.
- Abnormal gearbox rattle or clunking: Loose fasteners in the housing assembly create play between components, leading to metallic knocking sounds during acceleration.
- Intermittent gear engagement delays: When the screw fails to maintain clamping force, internal clearances shift, resulting in sluggish shifts or temporary loss of drive.
- Increased vibration at highway speeds: A compromised hex screw cannot dampen harmonic resonance, transmitting excessive vibration through the driveline.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0636.020.165 |
| Head Type | Hexagon (Hex) |
| Thread Size | M10 x 1.5 (estimated) |
| Length | 35 mm (estimated) |
| Material | High-tensile steel, zinc-plated |
| Weight | 0.045 kg (approx.) |
| OEM Reference | ZF 0636.020.165 |
| Torque Spec | 45 Nm (factory recommendation) |
Compatibility
This hexagon screw is validated for the ZF WG100, WG130, and WG131 transmission families. It also fits select WG180 and WG200 variants where the housing bolt pattern matches. For proper sealing, always pair with a new 4475280018 SCREW PLUG and inspect the 4143298457 SEAL KIT for wear during reassembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101009 | HOUSING | Main gearbox casing section |
| 4143301025 | HOUSING | Secondary housing cover |
| 0634313603 | O-RING | Seals housing joint |
| 4475280018 | SCREW PLUG | Closes oil passages |
| 0501342341 | SUPPORT RING | Distributes clamping load |
| 4143298457 | SEAL KIT | Complete gasket set |
| 0634313591 | O-RING | Secondary sealing element |
| 0636101068 | CAP SCREW | High-strength fastener |
| 4143221013 | THROTTLE VALVE | Controls hydraulic flow |
| 0634304484 | O-RING | Valve body seal |
