mariner lower unit problems? PLEASE help with advice!

[illinoisbassfishin]

I have a 1983 Mariner 115 inline 6 outboard motor I am having troubles with in the lower unit. I was thinking about draining my lower unit oil out but I asked around to different people and dealerships and asked if I should drain it out or not since I might still be using once or twice a month through the winter and a power plant lake. Everyone told me if you are going to use it not to mess with winterizing anything so I didn't. I went out to the garage one morning and the prop would not turn and the lower unit was froze up and there was a little bit of oil on the ground and some oil on the sides of the motor where it trickled out of the vents where water goes into the motor for the water pump (the vents that you would put a set of muffs over to run it out of the water with a water hose.) About a week later we got a warm spell and it thawed out and it would turn freely with no problems. We then drained the oil and there was a whole bunch of water in the lower unit mixed in the the oil. The lower unit has 2 plugs 1 on top and 1 on the bottom. The one on the bottom didn't have a rubber o-ring on it and the top one did so I'm guessing there's 1 way the water could have gotten in. I don't see any cracks in the casing where the water could have expanded and made it crack so I think I am good there. Does anyone have any opinions as to what might have went wrong? Since there was oil dripping out of the waterpump vent is it possible that the water expanded and busted the seals in the lower unit and I could just put new seals in it and I'd be good to do? Any help would be appreciated.

 

[fdcarlin]

Re: mariner lower unit problems? PLEASE help with advice!

i would recomend starting with vacuum and pressure test on the lower unit, that would tell you if the seals need to be replaced or not.

 

[jeffersondodson561]

Re: mariner lower unit problems? PLEASE help with advice!

Pressure test first, it is better that the lower unit be removed, it should hold 12-14 psi for 10 minutes, if you have leaks you can find them with a squirt bottle of soapy water, spray on suspected areas if you see bubbles that is where one potentional leak is. If your pressure test holds vaccum test--should hold 5 in/hg for 5 minutes. If you find a leak reseal the entire lower unit, and yes oil should be drained when performing tests.

 

[j_martin]

Re: mariner lower unit problems? PLEASE help with advice!

What went wrong is that you got some bad advice. The reason we change the LU lube, or at least crack the drain plug and make darned sure clear lube comes out just before freezing weather is to avoid the trouble you're having.

Oil is cheaper than parts, and gaskets are cheaper than gears, shafts, and bearings. Don't cut corners in the maintenance and that engine will outlive you.

 

[illinoisbassfishin]

Re: mariner lower unit problems? PLEASE help with advice!

So if the prop is turning now that we got all the water out of it and re-filled the oil till we take it to the shop do you all think that gears and everything will be okay? Last time I used the motor it still worked great and everything like that it was just froze up the next time I checked it a few days after I used it last. I want to do water pump work to it anyways so I know its all good to go so I'm thinking about just having all new seals put in the lower unit anyways while it's at the shop. I sure hope I just don't have to have the whole lower unit rebuilt.

 

[j_martin]

Re: mariner lower unit problems? PLEASE help with advice!

Could be the only problem was the missing gasket. Do the pressure testing, and if it's good, don't waste considerable time and money replacing seals. If the test fails, you'll know exactly where it failed and can make reasonable decisions on the course of repairs.

If it runs good with no noise, it's probably fine. You can also turn it by hand when it's off and feel excess backlash or rough gears.

hope it helps
John

 

[illinoisbassfishin]

Re: mariner lower unit problems? PLEASE help with advice!

Thank you sir. I will have the pressure test done somewhere and see what happens. I was just preparing myself for the worse and hoping for the best. I figured since it froze it may have expanded and caused the seals to bust out and that's why it was leaking fluid out of the vents where water is sucked into the motor. We will see what happens when I get my tax returns back and I have the extra money to take it to the shop.