ZF 4644.251.039 SPUR GEAR for WG180 | OEM Genuine Part

Overview

The ZF 4644.251.039 SPUR GEAR is a precision-machined internal component engineered for the WG 180 series transmission. This OEM genuine part plays a critical role in transferring rotational force between parallel shafts, directly influencing gear ratio stability and overall drivetrain efficiency. Located within the main gear train assembly, the spur gear meshes with adjacent pinions to ensure smooth power delivery under heavy loads. The SKU 4644.251.039 is factory-matched to ZF’s exacting tolerances, making it a direct replacement for worn or damaged gears in commercial vehicle transmissions.

Symptoms of Failure

When the ZF 4644.251.039 spur gear deteriorates, operators often notice grinding noises during gear engagement—a distinct metallic chatter that intensifies under acceleration. Another common symptom is erratic gear slipping, where the transmission unexpectedly drops out of gear, especially when climbing grades. You may also observe metal debris in the transmission fluid during routine oil changes, indicating tooth surface fatigue. Finally, vibration through the shift lever at specific RPM ranges signals uneven wear on the gear’s tooth profile, requiring immediate inspection.

Technical Specifications

Compatibility

This spur gear is primarily designed for the ZF WG 180 series, but it also fits select variants of the WG 200 and WG 150 transmissions where the gear train layout matches. Always verify the tooth profile and shaft diameter against your existing assembly. The gear integrates directly with the 4644101223 TRANSMISSION HOUSING and the 4644301225 TRANSMISSION HOUSING to maintain proper shaft alignment. For identification purposes, the 0730365125 TYPE PLATE should be cross-referenced to confirm transmission model. Additionally, the 4644301298 COVER PLATE must be removed for gear access during replacement.

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