ZF 6006.021.019 FS SG 4 for WG180 | OEM Genuine Part

Overview

The ZF 6006.021.019 FS SG 4 for WG180 is a precision-engineered synchronizer assembly designed to facilitate smooth gear engagement within the WG 180 series transmission. This OEM genuine part, identified by SKU 6006.021.019, sits directly on the main shaft and works in concert with the TRANSMISSION HOUSING to ensure reliable power transfer. As a critical wear component, it manages rotational speed matching between gears, reducing shift shock and extending the life of the entire drivetrain. The 6006.021.019 unit is manufactured to ZF’s exacting tolerances, making it a direct replacement for failed synchronizer rings in heavy-duty applications.

Symptoms of Failure

• Grinding or clashing noises during gear shifts: When the synchronizer wears, it fails to match shaft speeds, causing audible metal-on-metal contact when engaging forward or reverse gears.
• Hard shifting or gear lockout: A worn 6006.021.019 often prevents the shift collar from sliding fully, leading to resistance or complete inability to select a gear, especially in cold operating conditions.
• Oil contamination with metallic debris: As the synchronizer cone degrades, fine metal particles circulate through the transmission fluid, often visible during drain intervals and accelerating wear on the OUTPUT FLANGE.
• Delayed engagement after clutch release: A failing synchronizer causes a noticeable lag between pedal release and gear engagement, particularly under load or during rapid shifting sequences.

Technical Specifications

Compatibility

This synchronizer assembly is specifically designed for the ZF WG 180 series transmissions, commonly found in medium-duty trucks and industrial equipment. It also fits select WG 200 variants where the synchronizer hub dimensions match. The 6006.021.019 is not interchangeable with older FS 3 or FS 5 series units. For proper installation, ensure the DISCONNECTION mechanism is correctly aligned with the shift fork. Always verify housing compatibility with the TRANSMISSION HOUSING part number before ordering.

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