LOWER UNIT OIL CHANGE

[troyo]

I need to change the oil in the lower unit as it has been a little more than a year since it was last done; back then, I could afford to pay someone to do it, now I can't, so I will attempt it myself; here are the directions from Nissan Marine, and it sounds easy enough; how do I know how much is enough ? the chart shows appx 30.4 ozs., can I put too little or too much ? Does oil need changing anywhere else ? What about the impeller , any links on how to do that, and if it is neccessary to do every year ? Thanks for the help ! Nissan Marine

 

[grandx]

Re: LOWER UNIT OIL CHANGE

Not an expert with a nissan, but most lowers have two ports, a drain/fill port down low and a vent up higher. Remove lower then upper to drain. Then fill from lower until new oil appears floweing through vent. Cap off vent first then plug lower fill and it's done. It is also a good idea to replace the seals on the fill and vent screws at this time. Also inspect your old oil after draining looking for water or excessive metallic shavings.

 

[petryshyn]

Re: LOWER UNIT OIL CHANGE

Hey troyo:<br /><br />Ditto on the shavings grandx!!!<br />What a neat website. Its kind of interesting how nissan doesn't demand marine hypoid gear oil. If you check your oil often (and you should) the auto oil will work fine. There is nothing more satisfing than to drain your oil often, only to see its nice and clean. I change mine as often as it gets dirty, or atleast once a year.(don't forget, we have a short season). I used to overhaul gear boxes years ago. There is nothing more devastating than a oil related failure. What a shame. Most of them could have been prevented with a proper level of clean oil. If you're not adament about checking your oil as I am, go with OEM gear oil (more protection, mixes with water, no pooling causing rust or freeze damage)<br /><br />Cheap insurance and seal integrity check....change oil often!!!!<br /><br />my humble opinion.....

 

[troyo]

Re: LOWER UNIT OIL CHANGE

What do I do if I find shavings or water in the oil ???

 

[wippb]

Re: LOWER UNIT OIL CHANGE

Hey troyo<br />If you find water or the oil is the colour of coffee with cream you should have the lower unit seals checked. They will probably need changing. A pressure test will confirm this. A few small shavings are normal and it should look like sparkles in the oil. This is normal wear on the lower unit gears. Chunks are a problem. Go for it though, you will be suprized at how easy it is and you can't get it explained any better than that web site does.<br />Good Luck

 

[petryshyn]

Re: LOWER UNIT OIL CHANGE

Small amount of shavings is normal. There the result of the jump clutch mechanism used to shift in and out of gear. People who shift into gear slowly and with caution have more filings. (hard on mechanism) If you find shavings, change oil more often. You don't need them circulating through the gears and bearings. Some get trapped on the drain magnet, others are suspended in the lube and can only be removed by an oil change.<br /> I don't like any water in the gear box. Some people put up with it and change oil often. I prefer to repair problem. If you have water present, drain thoroughly, refill to proper level, replace fill and vent screw gaskets and try again. The gaskets may have caused the problem. Too many people overlook this common failure. If the water still gets in, do a pressure vacuum test and determine source of leak. Or use the shot-gun approach if you don't have the tools.(replace all seals, gaskets and o-rings) My neighbor has gotten away with a substantial leak in his old merc box for years. He changes his oil every couple months and it's a milkshake. It just won't fail on him!! pees me right off.....LOL<br /><br /><br />my .01 cent worth