ZF 0636.305.004 SCREW PLUG for WG150 | OEM Genuine Part

Overview

The ZF 0636.305.004 SCREW PLUG is a critical sealing component engineered specifically for the WG150 and WG200 series transmissions. This OEM genuine part, identified by SKU 0636.305.004, functions as a threaded closure that seals fluid passages within the transmission housing assembly. It prevents pressurized oil from escaping at key access points, ensuring the hydraulic system maintains proper pressure for clutch engagement and gear shifts. The screw plug is typically installed directly into the TRANSMISSION HOUSING or the TRANSMISSION HOUSING to secure fluid integrity during operation.

Symptoms of Failure

• External oil seepage around the plug threads: A worn or damaged 0636.305.004 screw plug often causes visible oil drips beneath the transmission, particularly after extended highway driving.
• Low transmission fluid warning with no visible pan leak: When this plug fails, fluid escapes slowly through the housing bore, leading to intermittent low-pressure warnings and erratic shifting behavior.
• Whining noise during gear engagement: A compromised seal allows air ingestion into the hydraulic circuit, producing a high-pitched whine as the pump struggles to maintain pressure.
• Burning clutch smell from fluid starvation: Progressive fluid loss through a failing screw plug can starve the clutch packs, generating a distinct burnt odor during operation.

Technical Specifications

Compatibility

This screw plug is a direct fit for ZF WG150 and WG200 series transmissions. It is commonly used in WG180, WG200, and WG150 models found in medium-duty trucks, buses, and off-highway equipment. The part interfaces with both the TRANSMISSION HOUSING and the TRANSMISSION HOUSING variants. For identification, always verify the TYPE PLATE on your unit to confirm model compatibility. Additionally, the GROOVED STUD is often replaced concurrently when servicing the plug bore.

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