I changed the drive lube from the bottom without taking the top plug out. Filling from bottom to Reservoir bottle. I didn't take the top plug out because I didn't feel like taking the external steering off to get a straight shot at the plug. Do you think I trapped any air?

doubt it, just fire it up burp any air out and top it off

Actually, what you did is the preferred way of doing it.

That's good to know. I thought it was ok, I really didn't feel like dropping the steering again, I just finished putting it back on after changing the fluid in it.

Same way I do mine.

So it is not necessary to remove the top plug while changing the drive oil? I was always under the impression without doing so it would allow air pockets to form? Changing the oil with the top plug in has no adverse effect vs taking it out for the oil change? Just curious because in my application it isn't the easiest to access either.

starting the boat and letting it run in gear will push out any air tapped inside?

It seems as long as you have reservoir its not needed to remove the plug. I just wanted to double check. Mine took the correct amount. I stopped as soon as I saw it in the bottle. Waited 1/2 hour for it to burp and continued to the final level. Makes life a little easier now

I personally don't do the outdrive oil - I have a marina do it before winter storage. When the boat goes into storage for the winter the reservoir is full. When I pull the boat out in the EARLY spring the reservoir is always low -- I fill it up and run it. Another bubble of air will show its ugly head in about and 1 hour of running - I top he reservoir off and I'm good to go for the season.

3pointstar

yes , with certain applications it makes it much easier to fill without taking the plug out. hence my thought on weather it causes air pockets or not without removing the plug while filling.