Overview
This OEM genuine ZF 0636.100.204 countersunk screw is a critical fastening element within the WG100, WG130, and WG131 transmission assemblies. Designed to secure internal components with a flush, low-profile fit, this screw prevents unwanted movement and maintains precise tolerances inside the gearbox. The SKU 0636.100.204 is engineered to withstand high shear loads and vibration, ensuring that adjacent assemblies—such as the 4699101093 HOUSING and the 4699301175 HOUSING—remain firmly anchored during operation. Without this fastener, the structural integrity of the transmission’s internal architecture is compromised.
Symptoms of Failure
- Transmission oil seepage around bolt heads: A loose or stripped countersunk screw can break the seal between mating surfaces, allowing fluid to escape past the 0634303936 O-RING.
- Abnormal gear rattle or clunking under load: When this fastener loses clamping force, the 4699301041 COVER may shift, creating excessive clearance and audible noise.
- Intermittent gear engagement hesitation: A failing screw allows micro-movement of internal plates, causing delayed or erratic shifting patterns.
- Metal debris in transmission fluid: Worn threads from a degraded countersunk screw can shed particles, contaminating the hydraulic circuit.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 0636.100.204 |
| Type | Countersunk Screw (DIN 7991 / ISO 10642) |
| Thread Size | M8 x 1.25 (estimated) |
| Length | 25 mm (estimated) |
| Head Style | Flat 90° countersunk, hex socket drive |
| Material | High-tensile steel, zinc-plated |
| Weight | ~12 g |
| OEM Reference | ZF 0636.100.204 |
| Torque Spec | 22 Nm (recommended) |
Compatibility
This countersunk screw is engineered for ZF WG-series transmissions, specifically the WG100, WG130, and WG131 models. It is also commonly found in select WG180 and WG200 variants where similar housing-to-cover interfaces exist. Always verify the thread pitch and length against your specific assembly. For complete sealing integrity, pair this screw with a new 0634303936 O-RING during reinstallation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699101093 | HOUSING | Main transmission casing |
| 4699301175 | HOUSING | Intermediate housing section |
| 4699301041 | COVER | End cover plate |
| 0634303936 | O-RING | Fluid seal for mating surfaces |
| 0630513203 | SNAP RING | Axial retention for shafts |
| 0750110302 | SHAFT SEAL | Prevents oil leakage at output shaft |
| 0630513073 | SNAP RING | Internal retaining ring |
| 0501319149 | SCREW PLUG | Drain or fill port plug |
| 0636302022 | SCREW PLUG | Pressure port plug |
| 0634801038 | SEALING RING | Copper washer for plug sealing |
