Cummins 3942535 Crankshaft Front Oil Seal

The Cummins 3942535 is a crankshaft front oil seal designed for Cummins C-series 8.3L diesel engines including 6CT, 6BT, ISC, ISL, QSC, and QSL models. It seals the front crankshaft journal against the timing gear cover to retain engine oil and exclude contaminants. Constructed from high-temperature resistant nitrile rubber (NBR) or fluoroelastomer (FKM) with a metal case and garter spring for consistent radial load. This component is critical for maintaining crankcase vacuum and preventing front main oil leaks in heavy-duty applications. Direct OEM replacement for Cummins part numbers 3942535, 3921927, 4024883, 3908139, 3941786, 4025270, and 3935959. Compatible with aftermarket cross-references including National 39804, Pai Industries 136142, and G&T Engine Parts M-3942535. Suitable for use in construction machinery, agricultural equipment, industrial power units, and on-highway trucks equipped with Cummins 8.3L engines.