ZF 4646.131.031 FILLER NOZZLE for WG251 | OEM Genuine Part

Overview

The ZF 4646.131.031 FILLER NOZZLE is a precision-engineered fluid delivery component designed exclusively for the WG 251 series transmission. This OEM genuine part ensures accurate and controlled oil flow into the transmission housing during assembly, service, or refill operations. Positioned at the upper port of the main casing, the filler nozzle directs transmission fluid directly into the sump area, preventing spillage and ensuring proper lubrication of internal gears and clutches. The SKU 4646.131.031 is manufactured to ZF’s exacting tolerances, guaranteeing a secure seal and consistent performance in heavy-duty industrial applications. When installed alongside the TRANSMISSION HOUSING and the HOUSING, this filler nozzle completes the critical fluid path that keeps your WG251 operating at peak efficiency.

Symptoms of Failure

When the ZF 4646.131.031 filler nozzle wears out or becomes damaged, operators may notice several distinct failure indicators. Oil leaks at the filler port are the most common symptom, often appearing as drips or wet spots around the nozzle base during operation. Gear slipping under load can occur if the nozzle cracks or deforms, allowing air to enter the hydraulic circuit and reducing line pressure. Erratic shift timing is another telltale sign, as insufficient fluid volume from a compromised nozzle leads to delayed clutch engagement. Finally, visible fluid spray during refill indicates the nozzle’s internal guide has failed, causing fluid to bypass the intended path and potentially contaminating the COVER assembly.

Technical Specifications

Compatibility

This filler nozzle is specifically engineered for the ZF WG 251 series transmission, but its design also supports several other heavy-duty ZF models that share the same fluid port geometry. Compatible transmissions include the WG180, WG200, WG210, and WG250 series, all of which utilize the same filler port location and thread specification. For proper installation, ensure the mating surface on the TRANSMISSION HOUSING is clean and free of debris. The nozzle is secured using a CAP SCREW that must be torqued to 25 Nm to prevent leaks. Always verify your transmission’s serial number against ZF’s compatibility chart before ordering.

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