ZF 4657.036.301 6 WG 191 Powershift Transmission Assembly | Complete Unit

Overview

The ZF 4657.036.301 6 WG 191 Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway machinery. This assembly integrates the full gear train, clutch packs, and hydraulic control system into a single, ready-to-install package. As a core component of the WG 191 series, it governs torque distribution and speed range selection under high-load conditions. The SKU 4657.036.301 identifies this as a complete unit, eliminating the need for piecemeal rebuilding. It sits directly between the engine bellhousing and the final drive, with the TRANSMISSION HOUSING providing structural integrity for the entire assembly.

Symptoms of Failure

• Delayed or harsh gear engagement: When the unit wears, hydraulic pressure drops, causing a noticeable lag or clunk when shifting from neutral to forward or reverse.
• Internal oil leaks and fluid loss: Worn seals within the assembly lead to external drips or a steady stream of transmission fluid, often visible around the mating surfaces of the HOUS.FRONT SECT.
• Gear slipping under load: The transmission may momentarily lose power during uphill travel or when carrying heavy payloads, indicating worn clutch discs or a failing torque converter.
• Unusual whining or grinding noises: Bearing wear or gear tooth damage produces a metallic sound that increases with engine RPM, signaling imminent internal failure.

Technical Specifications

Compatibility

This complete unit is engineered for the ZF WG 191 series, but its mounting pattern and gear ratios also allow direct fitment into the WG 180 and WG 200 series transmissions used in agricultural tractors and construction loaders. It is not compatible with the older WG 150 series without significant adapter modifications. For a full rebuild, ensure the HOUSING REAR PART and CYLINDRICAL PIN are inspected for wear during installation.

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