I/O fluid change

[angler0520]

i have a straight 4 mercruiser with a alpha one drive with the fluid monitering tank on it what is the correct method to change the lower unit oil?

 

[Gary H NC]

Re: I/O fluid change

I always use a small C-clamp and clamp the hose off near the transom to save whats in the monitor tank.
Then remove the lower drain and upper vent plug.
Drain it then fill slow from the bottom plug until it comes out the vent hole.
Put the vent plug in then the drain plug.Top off tank if needed.

After you run it and it sets overnight you may need to top off the tank again.

I'm sure other guys have different methods but that always worked fine for me.

 

[Philster]

Re: I/O fluid change

http://www.mercstuff.com/driveoil.htm

 

[Gary H NC]

Re: I/O fluid change

http://www.mercstuff.com/driveoil.htm

Good info...I guess i will not clamp off the bottle anymore...

 

[skargo]

Re: I/O fluid change

I drain my drive, and let it drain for a couple hours. When I fill my drive with my homemade weedsprayer filler upper device, and when I notice it filling my monitor bottle, I stop and fill the bottle from the top.

Couple pics of my filler.