ZF 4644.026.181 WENDEGETRIEBE Powershift Transmission Assembly | Complete Unit

Overview

The ZF 4644.026.181 WENDEGETRIEBE Powershift Transmission Assembly is a complete, factory-matched unit designed for the demanding environment of industrial drivelines. This assembly integrates the reversing gear set and clutch pack within the WG 200 Series architecture. As a “WENDEGETRIEBE” (reversing transmission), it enables seamless directional changes without stopping the vehicle, making it critical for wheel loaders, forklifts, and terminal tractors. The SKU 4644.026.181 represents a fully assembled unit, eliminating the need for individual component stacking. It sits directly between the torque converter and the output driveline, managing power flow through planetary gears. For proper installation, ensure the 4644105414 DISCONNECTION is correctly aligned to prevent hydraulic pressure loss.

Symptoms of Failure

• Delayed or harsh directional shifts: When the WENDEGETRIEBE wears, operators experience a noticeable lag when switching from forward to reverse, often accompanied by a jarring engagement.
• Oil leaks near the bell housing: Worn seals within the 4644.026.181 assembly cause transmission fluid to weep from the joint between the housing and the 4644101222 TRANSMISSION HOUSING, leading to low fluid levels.
• Gear slipping under load: Internal clutch pack degradation results in the transmission slipping during high-torque applications, such as climbing grades or digging.
• Unusual grinding noises during neutral-to-drive engagement: Damaged planetary gears produce a metallic grinding sound, indicating imminent failure of the complete unit.

Technical Specifications

Compatibility

This assembly is engineered for the ZF WG 200 Series transmissions, specifically the WG180 and WG200 models used in heavy equipment. It directly replaces the original unit in ZF 4WG-180 and 4WG-200 powershift transmissions. The 4644.026.181 is also compatible with select ZF 3WG-160 variants when paired with the correct 4644303409 OUTPUT FLANGE. Always verify the housing casting number before ordering. The unit requires the use of a 0636021083 HEXAGON SCREW for secure mounting to the transmission case.

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