ZF 4651.221.025 TUBE for WG100 | OEM Genuine Part

Overview

The ZF 4651.221.025 TUBE for WG100 is a precision-engineered fluid conduit designed to direct hydraulic oil flow within the valve body and clutch assembly of the WG 100 series transmission. This OEM genuine part, identified by SKU 4651.221.025, ensures consistent line pressure and lubrication to critical rotating components. It sits between the main control unit and the rotating clutch drum, acting as a rigid passageway that resists vibration and thermal expansion. Replacing this tube with the factory-specified component is essential for maintaining the calibrated oil flow that prevents premature wear on adjacent assemblies such as the TRANSMISSION HOUSING and the HOUSING.

Symptoms of Failure

• External oil seepage at the tube junction: A cracked or corroded 4651.221.025 tube often causes visible fluid drips near the bell housing, leading to low transmission fluid levels and eventual gear slipping.
• Erratic shift timing under load: When this tube develops internal restrictions or fractures, hydraulic pressure drops, causing delayed engagement between gears during acceleration.
• Whining or cavitation noise from the pump: A compromised tube allows air ingestion into the hydraulic circuit, producing a high-pitched whine as the pump struggles to maintain prime.
• Overheating of the transmission sump: Insufficient oil delivery due to a blocked or leaking tube reduces cooling flow, causing the transmission to run hotter than normal operating range.

Technical Specifications

Compatibility

This tube is engineered for the ZF WG 100 series, specifically the WG100, WG120, and WG150 models. It is not interchangeable with the longer tubes used in the WG180 or WG200 series due to differences in the HOUSING geometry. Always verify the transmission serial number against the OEM parts catalog before installation. The tube interfaces directly with the valve body and requires a new O-ring during reassembly to guarantee a leak-free seal.

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