ZF 0634.313.945 JUNTA TÓRICA para WG250/WG258/WG308 | Pieza Original OEM

Overview

This genuine OEM ZF 0634.313.945 JUNTA TÓRICA (O-ring) is a critical sealing component designed for the hydraulic control circuits within ZF WG250, WG258, and WG308 construction machinery transmissions. Positioned between the valve body and the main housing, this O-ring prevents pressurized transmission fluid from bypassing internal galleries, ensuring consistent clutch engagement and lubrication flow. The SKU 0634.313.945 is a direct factory replacement, guaranteeing the exact Shore hardness and cross-section required for long-term sealing integrity in heavy-duty off-highway equipment.

Symptoms of Failure

• External oil seepage at the transmission housing joint: When the 0634.313.945 O-ring hardens or flattens, pressurized ATF can escape around the 4143101016 HOUSING interface, leaving visible drips on the bell housing.
• Erratic gear engagement under load: A degraded seal causes internal pressure loss, leading to delayed or harsh shifting—especially when transitioning between forward and reverse in WG308 models.
• Low line pressure readings on the diagnostic port: Worn O-rings allow cross-leakage between circuits, reducing the hydraulic pressure needed to hold clutches engaged, often flagged as “slipping” during PTO operation.
• Contaminated transmission fluid with air bubbles: A compromised seal can aerate the oil, resulting in foamy fluid and increased operating temperatures.

Technical Specifications

Compatibility

This O-ring is engineered for ZF’s WG-series powershift transmissions used in construction machinery. Confirmed compatible models include WG250, WG258, and WG308. It also fits select variants of the WG180 and WG200 series where the valve body uses the same sealing groove. Always verify the groove diameter against your existing seal before installation. For full transmission overhaul, pair this O-ring with a new 4143301039 HOUSING and a fresh 0501318136 GASKET to prevent repeat failures.

Related Components