# Lower Unit - Lubricant Change



## Jpscott1 (May 2, 2017)

I have been changing lower unit oil on my outboards since I was a teenager.
My first motor was a 1974 Mercury 65hp.
Now that I have modern 4-strokes with EFI and computers/sensors etc-- the Lower Unit oil process has not changed- It is just a archaic as it was on that 1974 motor. 
You know the drill:
1. Take out the 2 screws (flathead screws- go figure)
2. Drain the oil.
3. Pump oil in from the bottom.
4. Insert top screw.
5. Quickly remove pump and insert bottom screw before all of the new oil drains out.

I think there needs to be some R&D done on this by the motor manufacturers. There has to be a better way!!!


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## Smackdaddy53 (Dec 31, 2012)

What could be changed that would make it better? Simplicity is golden.


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## Jpscott1 (May 2, 2017)

Smackdaddy- you may be right. I just think that the process of trying to install the bottom plug before the oil runs out is odd.


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## Smackdaddy53 (Dec 31, 2012)

Jpscott1 said:


> Smackdaddy- you may be right. I just think that the process of trying to install the bottom plug before the oil runs out is odd.


So maybe a threaded plug on bottom that you screw out and reveals a quick connect type fitting that is like a check valve on bottom where the lube tube connects and you fill until the lube reaches the top hole then pop the tube out of the bottom fitting and screw in a flush plug? 
Remember where you read this first so when it comes out later I get a rotalty check for every motor sold that has it...


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## Jpscott1 (May 2, 2017)

Smackdaddy- I think you solved it!


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## Smackdaddy53 (Dec 31, 2012)

Jpscott1 said:


> Smackdaddy- I think you solved it!


Back my idea with some money and we can split it 75/25...


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## TheAdamsProject (Oct 29, 2007)

It not as bad as you think when removing the bottom connection as when the unit is full and you screw back in the over fill screw it does create a little bit of a vacuum like when you place your finger over the top of a straw and pull it out of the glass. Granted it won't completely keeps it from dripping out but does hold it better than if the filler screw was out.


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## State fish rob (Jan 25, 2017)

Ive been doing it wrong for 40 years ! Still have evinrude lower unit oil in plastic caulk tube packaging. Hand squeeze .


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## Jpscott1 (May 2, 2017)

State fish rob--- I have never been a fan of using the "squeeze tube". I have always used one of the pumps. I just dont have enough hands/skill to get it done with the squeeze tube.


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## lemaymiami (Feb 9, 2007)

Just in case you think that nothing has changed in lower unit lubrication.. Along comes BRP and they're using a much longer maintenance interval than anyone else... The secret(s) are simple... The first thing they did was increase the lubricant capacity of their lower units (the lower units on the 90 E-Tec is actually what they were using on the old V-4 motors (much greater lubricant capacity...). and lastly the lower unit lubricant is fully synthetic and much more able to deal with any water intrusion.... 

Must admit that in years and years of running Johnson and Evinrude motors (all I've ever had since 1974...) I've never had a water intrusion problem in any of my lower units (despite knocking the skeg off of more than a few of them..). As for E-Tecs.. the only problem I ever had with a lower unit was pealing paint on one still under warranty. That was promptly solved with a brand new lower unit under full warranty....


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## jmrodandgun (Sep 20, 2013)

On the new Yamaha 425's you can change the lower unit oil with the motors in the water. It's just two tubes under the cowling. Pump out. Refill.


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## Guest (Nov 12, 2018)

Smackdaddy53 said:


> So maybe a threaded plug on bottom that you screw out and reveals a quick connect type fitting that is like a check valve on bottom where the lube tube connects and you fill until the lube reaches the top hole then pop the tube out of the bottom fitting and screw in a flush plug?
> Remember where you read this first so when it comes out later I get a rotalty check for every motor sold that has it...


Too complicated! You already have a drain pan sitting there so one little drip is nothing really. Just fill up, set top plug in hole leaving loose, give one more pump, tighten top plug, remove filler from lower hole, insert plug and tighten. The extra pump will assure you the lower is full without being over full and accommodate for the little that drips out when installing lower plug.


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## Smackdaddy53 (Dec 31, 2012)

Boatbrains said:


> Too complicated! You already have a drain pan sitting there so one little drip is nothing really. Just fill up, set top plug in hole leaving loose, give one more pump, tighten top plug, remove filler from lower hole, insert plug and tighten. The extra pump will assure you the lower is full without being over full and accommodate for the little that drips out when installing lower plug.


I agree, I was just entertaining his question with an answer.


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## Guest (Nov 12, 2018)

Smackdaddy53 said:


> I agree, I was just entertaining his question with an answer.


And with a very valid idea!


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## lemaymiami (Feb 9, 2007)

I deliberately didn't mention what BRP is doing with their G2 motors (second generation) since at present the smallest one is a 150hp.... It bears mention though, since it points the way to the future (and other makers have been watching....).
At any rate here's what they've done... They've added an additional tank for their lower unit lubricant - up above the lower unit in the area that normally only holds the linkage between power head and lower unit- connected by a clear tube so you can tell the condition of your lower unit lubricant at a glance (a very big deal in my opinion, since traditionally the only way you could ever have any idea of whether you've got water in your fluid would be to drain it....). The additional small tank allows the lower unit fluid to cool a bit then returns it as the engine is running....

Very cool - and a big step up from what every one else is doing.. Me ? I'm still waiting for G2 motors in the smaller sizes -particularly down to a 90 since that's what I run... Don't think they'll ever come all the way down to microskiff sized motors but I'm not well enough plugged in to know for sure...


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