Overview
The ZF 0636.404.298 CAP SCREW is a critical fastening component engineered specifically for the WG 65 series transmission assembly. This OEM genuine part secures the transmission housing cover and internal valve body sections, ensuring proper clamping force to maintain hydraulic pressure integrity. As a cap screw, it differs from standard bolts by featuring a precision-machined head designed for high-torque applications within the transmission’s oil-filled environment. The SKU 0636.404.298 is manufactured to ZF’s exacting tolerances, preventing fluid migration between chambers and supporting the structural alignment of the gear train. When installed alongside the 4616101065 TRANSMISSION HOUSING, this cap screw provides the necessary retention force to withstand continuous load cycling in heavy-duty commercial vehicles.
Symptoms of Failure
- Transmission fluid seepage at housing joints – A worn or stripped 0636.404.298 cap screw allows oil to escape past the mating surfaces, often visible as wet streaks along the WG65 casing.
- Abnormal gear engagement hesitation – When this fastener loses clamping torque, internal valve body clearances shift, causing delayed shifts or erratic clutch pack engagement under load.
- Vibration or rattle from the transmission bell housing – Loose cap screws permit micro-movement of the housing against the 0636011038 HEXAGON SCREW and adjacent fasteners, producing audible metallic noise during acceleration.
- Progressive oil loss requiring frequent top-ups – A compromised cap screw seal leads to gradual fluid loss, detectable by low dipstick readings and eventual overheating of the WG65 unit.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0636.404.298 |
| Type | Cap Screw (Hexagon Socket Head) |
| Thread Size | M10 x 1.5 |
| Length | 35 mm |
| Material | High-Tensile Steel (10.9 Grade) |
| Surface Finish | Zinc-Nickel Plated (Corrosion Resistant) |
| Weight | 0.042 kg |
| OEM Reference | ZF 0636.404.298 |
| Torque Specification | 45 Nm ± 5 Nm |
Compatibility
This cap screw is primarily designed for the ZF WG65 series transmission, but it also fits select models within the WG180 and WG200 families due to shared housing bolt patterns. The 0636.404.298 is commonly used in ZF 6-speed automatic transmissions found in municipal trucks, refuse vehicles, and heavy-duty construction equipment. For proper installation, always pair this cap screw with the 0636011118 HEXAGON SCREW for adjacent cover plates and the 0636016015 HEXAGON SCREW for oil pan retention. Verify compatibility by cross-referencing your transmission serial number with ZF’s OEM parts catalog before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101065 | TRANSMISSION HOUSING | Main structural casing for gear and valve body assembly |
| 0636011038 | HEXAGON SCREW | Secures oil pump cover to housing |
| 0636011118 | HEXAGON SCREW | Fastens valve body to transmission case |
| 0636016015 | HEXAGON SCREW | Retains oil pan and filter assembly |
| 0631306085 | CYLINDRICAL PIN | Aligns housing halves during assembly |
| 0634313118 | O-RING | Seals cap screw bore against fluid leaks |
| 0636304019 | SCREW PLUG | Closes hydraulic test ports in housing |
| 0634801152 | SEALING RING | Provides static seal under screw head |
| 0732611049 | FILTER INSERT | Traps debris in transmission oil circuit |
| 0634303718 | O-RING | Seals filter insert housing connection |
