ZF 0734.401.308 RECTANGULAR RING for WG90/WG94 | OEM Genuine Part

Overview

The ZF 0734.401.308 RECTANGULAR RING is a precision-engineered sealing component designed for the WG90 and WG94 series transmissions. This OEM genuine part sits within the transmission housing assembly, where it creates a critical static seal between mating surfaces to prevent fluid migration and maintain hydraulic pressure integrity. The rectangular cross-section of this ring, identified by SKU 0734.401.308, provides superior sealing force compared to standard O-rings, making it essential for high-pressure zones within the gearbox. When installed correctly, this ring works in concert with the 4661101001: TRANSMISSION HOUSING and the 4661301007: HOUSING to ensure leak-free operation under demanding industrial loads.

Symptoms of Failure

• External oil seepage at housing joints: A worn 0734.401.308 rectangular ring often causes visible transmission fluid leaks around the mating flanges of the WG90 or WG94, particularly near the 4661301093: TUBE connection points.
• Gradual pressure loss during operation: As the ring flattens or cracks, internal hydraulic pressure drops, leading to sluggish gear engagement and delayed shifting under load.
• Contaminated transmission fluid: A failing seal allows external debris to enter the system through gaps, often detected during routine oil analysis as increased particulate counts.
• Audible whining from the transmission: Reduced sealing efficiency can cause cavitation in the hydraulic circuit, producing a high-pitched noise that intensifies with RPM.

Technical Specifications

Compatibility

This rectangular ring is specifically engineered for ZF WG90 and WG94 series transmissions, which are commonly found in medium-duty trucks, buses, and construction equipment. The 0734.401.308 part is also compatible with the WG180 and WG200 models when used in conjunction with the 0631306174: CYLINDRICAL PIN for proper alignment. It fits all WG90 and WG94 variants, including those with integrated retarders, and is a direct replacement for original factory seals. Always verify the housing condition—if the 4661101001: TRANSMISSION HOUSING shows scoring, replace it simultaneously to ensure a proper seal.

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