ZF 4644.306.201 PISTON for WG 180/WG 200 | OEM Genuine Part

Overview

The ZF 4644.306.201 PISTON is a critical hydraulic actuation component engineered for the WG 180 and WG 200 series transmissions. This OEM genuine part functions as the primary force-transmitting element within the clutch or brake piston assembly, converting hydraulic pressure into mechanical movement to engage or disengage gear sets. Positioned inside the TRANSMISSION HOUSING, the piston must maintain a precise seal and smooth travel to ensure proper shift timing. The SKU 4644.306.201 is manufactured to ZF’s exacting tolerances, guaranteeing a direct fit without modification.

Symptoms of Failure

• Delayed or harsh gear engagement: A worn 4644.306.201 piston can cause sluggish shifts or abrupt clunking as hydraulic pressure bleeds past the seal.
• Internal transmission oil leaks: Cracks or scoring on the piston face allow ATF to bypass, leading to low line pressure and visible drips from the bell housing.
• Slipping in forward or reverse gears: Insufficient piston stroke reduces clutch pack clamping force, resulting in power loss under load.
• Erratic shift patterns: A sticking piston may cause intermittent neutral conditions or unexpected gear hunting during operation.

Technical Specifications

Compatibility

This piston is specifically designed for the ZF WG 180 and WG 200 transmission families. It is also a direct replacement in the WG 100 Series and WG 201 Series, where the hydraulic piston assembly shares identical bore dimensions. The 4644.306.201 works in conjunction with the DISCONNECTION mechanism and the OUTPUT FLANGE to complete the power flow path. Always verify the piston’s free movement by checking the HEXAGON SCREW torque specifications during installation.

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