AMS Oil 75W90 or Evinrude Lower Unit Gear Oil

mosalf

Cadet
Joined
Aug 3, 2023
Messages
13
Wanting to replace oil on my 1964 9.5HP Evinrude. Which oil should I go by? Amsoil is almost half price to the Evinrude Oil, however I will depend on you guys to give me the best solution here.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,446
As mentioned a Marine Grade Gear Oil will be fine, as the unit is not a Hypoid Gear design.
 

mosalf

Cadet
Joined
Aug 3, 2023
Messages
13
Hey I got Wallmart oil 80W-90 GL5. Will this work. Can anyone share the procedure for changing oil? I got the Supertech Gear Oil. Please advise if I can use this oil on a 1982 4HP Evinrude as well as the 1964 9.5HP evinrude. Look forward to your comments.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,818
With motor in normal running position.----Fill from bottom till it comes out the top.-----Install top plug.-----Remove filling device.----Install bottom plug.
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,440
With gaskets on the plugs.....
with NEW gaskets on the plugs :)

btw not certain about GL-5 oil...someting to do with sulfur ... may as well just stick with marine grade stuff as opinions differ widely..
 
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iggyw1

Ensign
Joined
Oct 24, 2011
Messages
954
I've had boats & motors for years, some really old and some newer ones. I used SuperTech lower unit oil in all of them and I never had a problem with this oil. My first motor froze & broke the housing in the winter because of water in the lower unit. Since that day, I drained the lower units in the fall every year before the freeze here in case there was any water in the units, and refilled them right after draining them. The old oil looked like new every year and never had a gear problem. I would suggest changing oil in them before winter storage if you live in a cold climate. I learned the hard way, so I am passing this along to you.
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,440
now 74 had motors since 17 and same process..change oil annually check for water !! before freeze up.

my ETEC did have creamy stuff one year but GC pressure test was OK and new gaskets solved the problem

the sulfur thing....just a friendly heads up. lots of stories in the Net.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,903
Dino oils have Extreme Pressure Additive (EP) of sulurized olefins and phosphorus. The also contain "yellow metal" sulfur buffering additives used for anti-corrosion that keep sulfur chemistries from attacking any copper alloy (brass or bronze) components. Synthetic oils have high heat range,less resistance and better shear.
 
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