Chainging oil in lower unit.

[JamesM56alum]

So i'v got what i believe to be a mid 60's 5.5 seahorse which i'v drained all the fluid out of tonight and i plan on replacing the fluid with either lucas lower unit oil or amsoil outboard, both are in the same price range so that's not an issue, my only concern is the fluid was milky and obviously i realize that some contamination is normal and that's why i'm leaning more toward's the amsoil since it's supposed to handle up to 10% water contamination before it loses it viscosity, but lucas on other hand i have used for year's in every thing from bearing's to motor oil, i feel like i'm cheating lol

 

[crazymanme2]

Milky oil = bad seals

 

[JamesM56alum]

It wasn't too bad i'm not all that worried about it because the lube was BLACK and didn't look like it had been changed in awhile and it had the burnt axle grease smell so i know it was old, so if it's been that long and the oil was just barely milky then i think i'm okay. You can see in the pic it's a little milky but not too bad, sorry it's a crappy pic also.

 

[aeviaanah]

It wasn't too bad i'm not all that worried about it because the lube was BLACK and didn't look like it had been changed in awhile and it had the burnt axle grease smell so i know it was old, so if it's been that long and the oil was just barely milky then i think i'm okay. You can see in the pic it's a little milky but not too bad, sorry it's a crappy pic also.

That looks pretty good. Remember top hole is the vent and bottom is where you fill it, till oil spews from top hole!

Good luck

 

[cajuncook1]

Change your lower unit oil with any good 80wt to 90wt marine grade gear lube of your choice.

Make sure you have new plastic or fiber washer that goes to both the drain plug and the air vent plug above. Those little plastic or fiber washers crack or leak over time. That is why at the end of each season it is recommended to drain the lower unit to evaluate your gear lube to check for water. Also when the lower unit is refilled new plastic or fiber washer are replaced.

After a couple of outings, check your check your gear lube. If it is contaminated with water and looks a little milky then, crazymanme2 is right, time to check your lower unit seals, drive shaft seals and shift rod seal.

***Check to make sure 2 plastic or fiber washer are not in place. Sometimes they are pushed by the screw plug and aren't seen, so someone will put another one thinking there was no washer to start off with. This can certainly lead to water intrusion into the gear case due to insufficient sealing.


Here is link to digital diagram of your motor. (I assume it is 1964 Evinrude 5.5hp...it was the last year they made the 5.5hp)

https://www.marineengine.com/parts/vintage-evinrude-johnson/278539/catalog.html?https://www.marineengine.com/parts/vintage-evinrude-johnson/278539/27853900001.htm


Here is a diagram and parts list of the lower unit of a 1964 Evinrude 5.5hp (it does not show the washer, but it is there, I promise!!) Item #22 top and bottom plug

 

[JamesM56alum]

Wow thanks alot, i was hoping to find a diagram for this motor but you saved me alot of time looking!