ZF 4644.026.197 6 WG 200(555/5) Powershift Transmission Assembly | Complete Unit

Overview

The ZF 4644.026.197 6 WG 200(555/5) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway machinery. This assembly integrates the gear train, clutch packs, and hydraulic control system into a single, ready-to-install package. As the core of the WG 200 series, it manages torque distribution across six forward and one reverse gear, enabling smooth directional shifts under load. The SKU 4644.026.197 identifies this specific 555/5 ratio variant, which is critical for maintaining original equipment performance in loaders, graders, and industrial tractors. When replacing this assembly, ensure the 4644101164: TRANSMISSION HOUSING and 4644301371: TRANSMISSION HOUSING are inspected for cracks or wear, as they directly support the unit’s alignment.

Symptoms of Failure

When the ZF 4644.026.197 assembly begins to fail, operators typically notice these specific issues:

• Delayed or harsh engagement: A noticeable lag when shifting from neutral to forward or reverse, often accompanied by a clunking sound, indicates worn clutch discs or degraded seals inside the unit.
• Oil leaks at the bell housing: Fluid weeping from the joint between the transmission and engine, especially after prolonged operation, points to a compromised gasket or cracked housing. This is a common long-tail search query for “ZF WG200 oil leak repair.”
• Gear slipping under load: The transmission momentarily loses power during uphill climbs or heavy digging, with the engine revving but no corresponding wheel movement. This suggests internal hydraulic pressure loss or worn planetary gears.
• Unusual whining or grinding noise: A high-pitched whine in a specific gear range, or a grinding sound during shifts, signals bearing failure or debris contamination within the assembly.

Technical Specifications

Compatibility

This complete powershift assembly is engineered for the ZF WG 200 series, but it also fits select variants of the WG 180 and WG 150 families when using the correct adapter kit. Specifically, it is a direct replacement for models 6 WG 200, 6 WG 180, and 6 WG 150 with the 555/5 ratio. The unit’s mounting flange matches the 0730365067: TYPE PLATE, which must be transferred to the new assembly for proper identification. Additionally, the 0631311009: GROOVED STUD is used to secure the assembly to the engine flywheel housing; always replace these studs during installation to prevent fastener fatigue.

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