Reply To: Substitute for OMC Shift O-ring #301877, Sierra 18-7100

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October 2, 2024 at 10:23 am #291267
LARRY CATON
Participant

    US Member

    I’m going to try some of the Mercury O-RING 25-85594 and see how well they fit. They’re OEM for Mercury and the Sierra 18-7100 is supposed to cross. The size is given as 0.239″ x 0.174″. That would make it a little snug on the shift shaft, and 0.578″ OD vs 0.555 OD on the OMC o-ring. That’s an OD difference of 0.023″. Interestingly, the ones I ordered are orange.

    I like to experiment. Who knows, the Mercury might make a better seal.

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