Probably a silly question but curious about lower unit

[dwhite1031]

I'm about to drain and replace my lower unit lubricant for the first time. I've never done it before....yes fellas...I am a maintenance virgin...pure and innocent...so please.....be gentle.....​

I read where you are supposed to fill the lower unit from the bottom plug hole. But my question is, won't you lose a siginificant amount of oil once you remove the tube to replace the plug? Or does the fact that the top plug is also out at the time create a sort of vacuum affect and prevent the law of gravity? Or is the loss small if you get the plug back in quick enough?​

Thanks,​

 

[ezmobee]

Re: Probably a silly question but curious about lower unit

Or is the loss small if you get the plug back in quick enough?

That's pretty much it. Work fast!

 

[daveswaves]

Re: Probably a silly question but curious about lower unit

I'm about to drain and replace my lower unit lubricant for the first time. I've never done it before....yes fellas...I am a maintenance virgin...pure and innocent...so please.....be gentle.....​

I read where you are supposed to fill the lower unit from the bottom plug hole. But my question is, won't you lose a siginificant amount of oil once you remove the tube to replace the plug? Or does the fact that the top plug is also out at the time create a sort of vacuum affect and prevent the law of gravity? Or is the loss small if you get the plug back in quick enough?​

Thanks,​

The top plug is out while you fill it, then you put the top plug in before you take the fill tube out of the bottom plug. Very little will run out as long as you put the top plug back in first. As you suspected, vacuum holds the oil back due to its viscosity.

 

[robert graham]

Re: Probably a silly question but curious about lower unit

Pump oil in bottom until it starts to come out the top, replace top plug and quickly replace bottom plug, not much will leak out since there's a bit of a vacuum in there and the plugs are relatively small. Use new washers/gaskets from the boat dealer. Quick and easy job, Good Luck!