ZF 4616.303.123 CYLINDER for WG65 | OEM Genuine Part

Overview

The ZF 4616.303.123 CYLINDER for WG65 is a critical hydraulic actuation component engineered for precise clutch and gear engagement within the WG 65 Series transmission. As an OEM genuine part, it serves as the primary pressure vessel that converts hydraulic force into mechanical motion, directly controlling shift quality and torque flow. This cylinder integrates seamlessly with the 4616101089 TRANSMISSION HOUSING to form a sealed, high-pressure circuit. The SKU 4616.303.123 is laser-etched for traceability and must match OEM specifications to avoid internal leakage.

Symptoms of Failure

• Delayed or harsh gear engagement: When the cylinder bore wears, hydraulic pressure drops, causing a noticeable lag or clunk when shifting between forward and reverse.
• External hydraulic oil leaks: Cracks or seal degradation on the cylinder body produce visible fluid seepage around the 0636011038 HEXAGON SCREW mounting points, often leaving puddles under the vehicle.
• Transmission slipping under load: A failing cylinder cannot maintain clamping force on clutch packs, resulting in RPM flare without corresponding acceleration, especially on inclines.
• Erratic shift patterns: Intermittent pressure loss causes the transmission to hunt between gears or fail to hold a selected ratio during steady-state driving.

Technical Specifications

Compatibility

This cylinder is specifically designed for the ZF WG 65 Series transmission family, which includes models such as WG65, WG80, WG120, WG150, WG180, and WG200. It is a direct replacement for units built between 2010 and 2023. The part interfaces with the 0636016015 HEXAGON SCREW for secure mounting and works in conjunction with the 0631306085 CYLINDRICAL PIN for precise alignment. Always verify your transmission serial number against the ZF parts catalog to confirm fitment.

Related Components