Lower unit maintenance

Discussion in 'Bubba's Outboards' started by sw2324, May 20, 2007.

  1. sw2324

    sw2324 New Member

    Messages:
    64
    State:
    Texas
    What is involved in lubing the lower unit of a 1992 Mercury 150? Does it just involve draining the old and adding new? If so, where do I get everything and is there any more maintenace I should do while there?
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Yup, that's all there is to it.

    Now for the proceedures of getting it done.
    Remove the plugs in the lower unit, top plug first, then the bottom drain plug. They look alike, but one's up just under the anti -cavitation plate and the other's in the lower area.

    Get the oil and equipment from Wal-mart.
    1 quart of lower unit oil and the pump that screws into that quart bottle to pump it into the lower unit from the bottom up.

    Fill it until the oil runs out the top hole. replace the plug/screw in the top hole first and then as quick as you can, install the bottom plug/screw as soon as you remove the pump hose.

    Also, be sure your pump will screw into a Merc lower unit.

    While your down there, remove your prop and thrust washer. Check for fishing line, then grease the shaft. replace all that you took off in reverse order.
     

  3. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    If you haven't all ready done so, I'd recommend a book for your particular motor. While my friend and I were servicing my lower unit, the fluid was pinkish. Oh no, said I, I have a bad seal. Went in and read my book. It said because I had one of t he Evinrude Electra shifts, if my lower unit seals ever leaked, I should take the motor in for inspection by certified mechanics due to the hydraulic pumps and electrical connections. So, I did. When they started to pull the prop shaft, the needle bearings fell apart in their hands. Had them replace every bearing in the lower unit, needed or not. It's too late when your on the water and the bearings go out. Did the water pump and impeller also. Then, to top it all off, the seal that joins the lower unit to the upper unit was bad and had to be replaced. Got that in yesterday, so will have it put together for Keystone V. But the book saved me untold horror and expense. I am thankful.
     
  4. john103

    john103 New Member

    Messages:
    71
    State:
    illinois
    Bobpaul, does this also apply to mine which is an 83' 15hp mariner. I recently picked it up and was told it was ok but to top it off, referring to lubing the lower unit, New to this also.
     
  5. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Yes, they're all about the same. Some small variations, as to which side the drain plugs are on.

    Just don't unscrew anything with a phillips head on it.
     
  6. JAYNC

    JAYNC Active Member

    Messages:
    1,312
    State:
    Newport N.C.
    The only thing I want to add is to replace the blue gaskets on the drain plugs every time, that is the biggest reason people get water in their lower units. All the other advise has been excellent.
     
  7. RIVER-RAT

    RIVER-RAT New Member

    Messages:
    3,128
    State:
    MO / MT
    I decided to change the gear lube in the lower unit today, not good.........when I took the plug out, the first thing that come flowing outta there was.........water.. Alot of water!

    Then a little bit of milky white oil came dribbling out. The only thing I can think of is this, last August when I damaged the prop shaft and all, it damaged the seal, so while going up river with the bent shaft it sucked water in there. Then when I took it to Cooks to get repaired, they must not have drained the gear lube and put the new seal in, therefore sealing in all the water.

    I don't know what to do, except try to drain all the old oil out and fill with fresh, then run it, then drain it again. Problem is, with the below normal temps outside (37*), that gear lube just doesn't want to flow, it's like grease! I need the weather to warm up so the oil can drain completely out! I can't really afford to take it back to cook's, that last trip wiped me out! I can in a few months when I get some money saved up. Any suggestions fellas????
     
  8. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Yes ,take it back to where you had it repaired. They should have changed the lower unit oil. In fact I don't see how they changed a prop shaft seal without loosing the oil. If I change on out I always pressure check it.

    You can always take a small torch and heat the lower unit uo some and drain the oil. Be sure to change the fill and drain screw gaskets.