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Lower Unit Lube Capacity Question

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  • Lower Unit Lube Capacity Question

    I did my first lower unit oil change yesterday. It was really easy, and I am now embarrassed that I paid to have the job done in the past.

    After draining the oil I started pumping in the new oil. The lower unit took in a full quart, and I never saw oil ooze out the top hole. Since I ran out of oil, I replaced the drain plugs. I then poured the old oil back into the quart bottle that the new oil came in. The amount of old oil was approximately the same as the new oil. I checked my manual for lower unit oil capacity information and could not find anything.

    Since I replaced approximately the same amount that I drained, do I need to worry about adding more oil? I think I will pick-up another quart of oil and pump until I see oil ooze out the top hole, but I would like knowledgeable opinions on this. Anyone know what the normal oil capacity is? My motor is a 1978 Johnson 140 hp V4.


  • #2
    Re: Lower Unit Lube Capacity Question

    Fill to it comes out the top hole.


    • #3
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      Re: Lower Unit Lube Capacity Question

      The listed capacity of your gearcase is 37.8 ounces. See page 2-6 of your factory service manual.

      But as 4.0l says, with the motor in running position, the case is full when the oil runs out of the vent hole. Too much oil and you can damage a seal when the oil heats up.