ZF 4699.003.013 GK20 | OEM Genuine Part

Overview

The ZF 4699.003.013 GK20 is an OEM genuine component engineered for the hydraulic control system within ZF heavy-duty powershift transmissions. This part functions as a critical valve or actuation element, managing oil flow to clutch packs and ensuring precise gear engagement under high torque loads. Located inside the main transmission housing, the SKU 4699.003.013 directly interfaces with the 4699101024 HOUSING and the 4699301077 HOUSING to maintain proper hydraulic pressure. Without this genuine ZF part, the transmission cannot achieve the required shift timing for construction machinery applications.

Symptoms of Failure

• Delayed or harsh shifting – When the 4699.003.013 wears internally, hydraulic pressure drops, causing sluggish engagement between forward and reverse gears. Operators often report a “clunk” when shifting under load.
• Transmission overheating – A failing GK20 valve can cause continuous oil bypass, generating excessive heat. This is frequently misdiagnosed as a cooler issue.
• Oil contamination in the bell housing – Worn seals on this part allow ATF to leak past the 4699301017 BEARING COVER, leaving visible drips on the chassis.
• Intermittent loss of drive – In severe cases, the valve sticks open, causing the transmission to default to neutral. This symptom is common in machines operating in dusty environments.

Technical Specifications

Compatibility

This genuine ZF part is designed for use in the following transmission models commonly found in wheel loaders, graders, and dozers:

• ZF WG180 – All series (WG180-I, WG180-II)
• ZF WG200 – Including WG200-I and WG200-II variants
• ZF 4WG-200 – 4-speed powershift versions
• ZF 6WG-200 – 6-speed heavy-duty models

Always verify that the 4699301085 COVER is also inspected during replacement, as misalignment can cause premature wear of the GK20 valve.

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