ZF 4699.804.079 GK25 | OEM Genuine Part

Overview

The ZF 4699.804.079 GK25 is a precision-engineered clutch pack assembly designed for the power shift transmissions used in heavy construction machinery. This OEM genuine part functions as the primary torque transfer element within the planetary gear set, engaging and disengaging specific gear ratios to control machine speed and direction. The SKU 4699.804.079 is a direct replacement for the original factory component, ensuring that hydraulic clamping forces are correctly applied to the friction discs. When installed, this part works in concert with the 4699004102: GK25 to maintain consistent pressure distribution across the clutch hub.

Symptoms of Failure

• Erratic gear engagement under load: When the 4699.804.079 wears, operators often report a noticeable delay or “clunk” when shifting from forward to reverse, particularly on inclines.
• Low transmission oil pressure warnings: Worn clutch discs allow internal leakage, triggering dashboard alarms for low hydraulic pressure during operation.
• Metallic debris in the oil filter: Friction material shedding from a failing GK25 assembly will contaminate the transmission fluid, visible as glitter or sludge during routine maintenance.
• Overheating in the torque converter circuit: Slipping clutches generate excessive heat, causing the transmission temperature gauge to spike above normal operating ranges.

Technical Specifications

Compatibility

This GK25 clutch pack is engineered for ZF’s heavy-duty powershift transmission series, specifically the WG180, WG200, and WG210 models commonly found in wheel loaders, dozers, and excavators. It is also compatible with the 4WG-200 and 6WG-200 variants used in mining and quarry equipment. The 4699.804.079 interfaces directly with the 4699101043: HOUSING to align the clutch drum, while the 4699102063: INPUT shaft drives the assembly. For proper torque flow, the 4699103026: OUTPUT hub must be inspected for spline wear during replacement.

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