ZF 4646.131.023 FILLER NOZZLE for WG250 | OEM Genuine Part

Overview

The ZF 4646.131.023 FILLER NOZZLE is a precision-engineered fluid delivery component designed exclusively for the WG 250 series transmission. This OEM genuine part, identified by SKU 4646.131.023, directs transmission fluid into the torque converter and hydraulic control system with exacting flow characteristics. Positioned at the upper port of the TRANSMISSION HOUSING, it ensures proper lubrication and cooling of internal clutches and planetary gears. Constructed from corrosion-resistant alloy, this filler nozzle maintains consistent fluid pressure across all operating temperatures, directly supporting shift quality and thermal management in heavy-duty applications.

Symptoms of Failure

• Transmission fluid leaking from the filler neck area — A cracked or degraded nozzle seal often causes visible drips near the bell housing, leading to low fluid levels and eventual gear slipping.
• Erratic shifting or delayed engagement — When the nozzle becomes clogged with debris, hydraulic pressure drops, resulting in harsh shifts or hesitation when moving from neutral to drive.
• Overheating during extended operation — A restricted filler nozzle reduces oil flow to the cooler circuit, causing transmission temperatures to spike above 230°F under load.
• Whining noise from the pump area — Air ingestion through a worn nozzle gasket creates cavitation, producing a high-pitched sound that intensifies with RPM.

Technical Specifications

Compatibility

This filler nozzle is engineered for the ZF WG 250 series, but it also fits select models in the WG 180, WG 200, and WG 210 families due to shared port geometry. It is commonly used in off-highway vehicles, wheel loaders, and industrial machinery where the HOUSING and COVER assemblies are identical. Always verify compatibility with your transmission serial number before installation. The nozzle integrates directly with the HEXAGON SCREW that secures the filler tube to the main casing.

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