Overview
The ZF 0636.101.852 CAP SCREW is a critical OEM genuine fastener engineered for the WG 251 series transmission. This precision-machined cap screw secures key internal assemblies, including the TRANSMISSION HOUSING and HOUSING components, ensuring proper clamping force and alignment under high-torque conditions. Designed to withstand extreme vibration and thermal cycling, the SKU 0636.101.852 replaces worn or stripped fasteners to restore structural integrity within the gear train. Without this cap screw, the COVER assembly may shift, leading to misalignment and premature wear of adjacent parts.
Symptoms of Failure
- Transmission oil seepage around the housing joint: A loose or fatigued cap screw allows the HOUSING seal to break, causing fluid to weep externally.
- Gear engagement hesitation or slipping: Insufficient clamping from a failed 0636.101.852 can permit axial play in the gear cluster, reducing torque transfer efficiency.
- Abnormal metallic rattling under load: When the cap screw loosens, the TRANSMISSION HOUSING may vibrate against internal components, producing a distinct rattle.
- Increased backlash in the drivetrain: Worn threads or a broken cap screw cause the CAP SCREW to lose preload, leading to excessive clearance between mating gears.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 0636.101.852 |
| Material | High-tensile alloy steel, zinc-plated |
| Thread Size | M12 x 1.75 |
| Overall Length | 45 mm |
| Head Type | Hexagon socket cap |
| Weight | 0.045 kg |
| OEM Reference | ZF 0636.101.852 |
| Torque Specification | 85 Nm (factory spec) |
Compatibility
This genuine ZF 0636.101.852 CAP SCREW is primarily designed for the WG 251 series transmission. It is also compatible with the WG 180, WG 200, and WG 250 series models where the same housing bolt pattern is used. Always verify thread pitch and length against your specific transmission assembly before installation. The cap screw works in conjunction with the TRANSMISSION HOUSING and COVER to maintain proper alignment across these platforms.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101072 | TRANSMISSION HOUSING | Main structural casing for gear assembly |
| 4646301201 | HOUSING | Secondary housing for auxiliary components |
| 4646301166 | COVER | Seals and protects internal gear mechanisms |
| 0636101051 | CAP SCREW | Alternate fastener for adjacent mounting points |
| 4646201018 | COVER SHEET | Gasket layer for fluid retention |
| 4646301277 | SCREEN SHEET | Filter mesh for hydraulic fluid |
| 4646201019 | COVER SHEET | Secondary sealing gasket |
| 0730365125 | TYPE PLATE | Identification label for transmission model |
| 0631311009 | GROOVED STUD | Threaded rod for alignment and fastening |
| 0636010216 | HEXAGON SCREW | General-purpose bolt for housing attachment |
