ZF 0636.020.016 HEXAGON SCREW for WG201 | OEM Genuine Part

Overview

The ZF 0636.020.016 HEXAGON SCREW is a critical fastening component engineered specifically for the WG 201 series transmission. This OEM genuine part secures the TRANSMISSION HOUSING assembly, ensuring precise alignment and clamping force within the gearbox casing. Positioned in the upper valve body and clutch pack retention area, this hexagon screw prevents axial movement of internal shafts under high torque loads. The SKU 0636.020.016 is manufactured to ZF’s exacting tolerances, making it a direct replacement for worn or stripped fasteners in heavy-duty industrial transmissions.

Symptoms of Failure

• Transmission oil seepage at housing joints: When the hexagon screw loses its torque retention, gaps form between the TRANSMISSION HOUSING sections, leading to fluid migration and external wet spots.
• Gear engagement hesitation or slipping: A loosened 0636.020.016 allows the THREADED BUSH to shift, altering clutch pack clearances and causing delayed shifts under load.
• Abnormal metallic rattling from the bell housing: Vibration-induced wear on the hexagon screw threads creates play in the SCREW PLUG seat, producing audible noise during gear changes.
• Torque converter shudder during low-speed operation: Inadequate clamping from a fatigued screw destabilizes the housing interface, transmitting vibration through the driveline.

Technical Specifications

Compatibility

This hexagon screw is primarily designed for the ZF WG 201 series transmission, but it also fits select models in the WG180, WG200, and WG250 families where M16 fasteners are specified for housing retention. It is commonly used in ZF 4WG-200, 5WG-200, and 6WG-250 off-highway transmissions found in mining trucks, agricultural tractors, and construction loaders. Always verify thread pitch and length against your specific housing bore depth before installation.

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