ZF 0634.305.026 RECTANGULAR RING for WG65 | OEM Genuine Part

Overview

The ZF 0634.305.026 RECTANGULAR RING is a precision-engineered sealing component designed specifically for the WG 65 series transmission. 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 provides superior sealing force compared to standard O-rings, ensuring reliable operation under high-pressure conditions. As an original equipment manufacturer component, the SKU 0634.305.026 guarantees exact dimensional tolerances and material composition required for optimal transmission performance. This ring is typically installed during transmission rebuilds or when addressing oil containment issues in the WG65 gearbox.

Symptoms of Failure

• External oil seepage around the transmission housing joint – When the rectangular ring hardens or cracks, transmission fluid begins to weep from the seam between the housing and cover, leaving visible oil residue on the exterior casing.
• Gradual pressure loss during gear engagement – A worn 0634.305.026 ring allows internal fluid bypass, resulting in delayed clutch pack engagement and a noticeable drop in line pressure during shifts.
• Contaminated transmission fluid from external debris ingress – A compromised seal permits dirt and moisture to enter the gearbox through the housing interface, accelerating wear on internal components like the filter insert and planetary gears.
• Increased operating temperature due to fluid starvation – Leakage past the rectangular ring reduces available hydraulic fluid volume, causing the transmission to run hotter than normal and potentially triggering overheat warnings.

Technical Specifications

Compatibility

This rectangular ring is primarily designed for the ZF WG 65 series transmission, but it also fits several other ZF powershift models that share the same housing interface design. Compatible transmissions include the WG65, WG80, WG100, WG120, WG150, WG180, and WG200 series. The part is also suitable for certain WG 55 and WG 70 variants where the housing joint dimensions match. Always verify the specific housing configuration before installation, as some models may require additional sealing components such as the 0634313118 O-RING or 0634801152 SEALING RING for complete assembly.

During installation, this rectangular ring works in conjunction with the 4616101059 TRANSMISSION HOUSING to create a leak-proof seal. The housing must be properly torqued using the correct fasteners, including the 0636011038 HEXAGON SCREW, 0636011118 HEXAGON SCREW, and 0636016015 HEXAGON SCREW, to ensure even compression of the ring. For complete transmission overhaul, additional sealing elements like the 0634303718 O-RING and 0636304019 SCREW PLUG should be replaced simultaneously.

Related Components

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