Changing lower unit grease on 40hp Hondas

Big Mac

Just curious how most of you change out the lower unit grease. Hot or cold? I have always had it done during service visits, but am going to do it myself this time. I changed out the impellors last year and checked the grease and saw no water so I left it alone. I am going to change the engine oil and filters before I drain the carbs so I could put the engines in gear while I warm them up, which should warm up the lower unit oil? Thanks in advance for any comments,Big Mac.

Captains Cat · Posted: Sat Nov 13, 2010 12:14 pm Post subject:

I've always done mine cold. Takes a little longer to drain but it will drain. Be sure to use NEW washers in the plugs, that's the source of a lot of water intrusion if you don't.

Unless you run it a long time, won't warm it up much in the water anyway Doesn't get very "hot" ever...

Charlie

Sea Wolf · Posted: Sat Nov 13, 2010 12:21 pm Post subject:

It will certainly drain faster if it's warm, so why not warm it up a bit?

Could use a portable electric heater to blow some warmth on it if necessary.

Or just let it drain overnight, or all week, if it's that cold in Washington!

Or you could move down to SUNNY California and change it in the summertime, no additional heat required!* Laughing

* Just for Roger/Dreamer, and others, who left it all behind. CoolSmile

Joe.

matt_unique · Posted: Sat Nov 13, 2010 4:29 pm Post subject: Lower unit

I have always changed mine at the same time save the 20 hour service. For me that means first of November in Massachusetts.

This is a silly detail to point out but it's actually 90w oil (not grease). I let mine run out for about 10 minutes. I make a point to have a clean oil pan so I can carefully inspect the oil for contaminants and water.

mjsiega · Posted: Sat Nov 13, 2010 5:22 pm Post subject:

Just curious, but if oil molecules are larger than water molecules, and after you change the lower unit oil and no oil is leaking out through the vent or fill hole, how can water get in through those holes?

mjsiega · Posted: Sat Nov 13, 2010 7:18 pm Post subject:

meant to say "if water molecules are larger than oil molecules".

Captains Cat · Posted: Sun Nov 14, 2010 11:15 am Post subject:

If there's a leak at a seal or a washer, oil can and will leak out. When that happens, there's a void and water can and will leak in... Crook

Charlie

seabeagle · Posted: Sun Nov 14, 2010 5:43 pm Post subject:

Odd? I thought the lower in my Honda 50 was 30w. Confused

jstates · Posted: Mon Nov 15, 2010 1:07 am Post subject: Changing lower unit lube Honda 40

Remember to re-fill from the bottom, to prevent trapping air.