NOK BH1517 Crankshaft Rear Oil Seal Assembly

This crankshaft rear oil seal is engineered to OEM dimensions of 85 mm inner diameter, 102 mm outer diameter, and 12 mm width. It features a nitrile butadiene rubber (NBR) sealing lip with a garter spring for consistent radial load retention across thermal cycles. The metal case provides structural rigidity for press-fit installation into the engine block rear housing. Designed for diesel engine crankcase environments, it resists degradation from engine oil, blow-by gases, and temperatures up to 120°C continuous operation. Compatible with Yanmar 3D84, 4D84, 4T84L, 4D88, 4TNV88, 3TNV88, 3TNV84, 4TNV84, 3TN78, and 4TNE88 series engines. Also fits Isuzu 3CD1, 3CD1T, 3CE1 and Kubota V2403 engine platforms. Commonly installed in Komatsu PC40 mini excavators and Yanmar EF series tractors. Replaces Yanmar OEM 129120-01780. Variants include BH1517E (NBR), BH1517F (VMQ silicone), and BH1517I (PTFE) for specific temperature and chemical resistance requirements.