I just changed the lower unit oil on my 1990 Johnson 15hp outboard and noticed that there was not gaskets or o rings on the screws. Is this ok? There was not any water in the lower unit.
No there should be a seal on the screws.-----Some screws have an o-ring in a groove.-----Double check and see if the nylon washer stayed in the housing.----Caution.----Make sure you have the screws sealed as the price of new gears / bearings will shock you.
I double checked and the gaskets/ o-rings were definitely not there. I bought original omc replacement gaskets (the same ones listed in the manual) but when I installed them the screws would not seat flush with the lower unit housing which worried me. What am I missing?
I think the drain plugs that year should have o-ring seals in the plugs themselves. If not, use what you have now. Won’t be exactly flush, but will seal your gearcase normally.
???----" Seal themselves "----That sounds good.-------Hopefully you have checked the price of gears and bearings should water get in there.------There have to be seals on those plugs !!!