I've read another post on these forums concerning changing the transmission fluid in the T355 manual gearbox. It was states in that posting to not use the top fill plug, but to use the side fill plug.
Just curious as to why I should not use the top rubber fill plug to pour transmission fluid into the transmission?
Why is that wrong, and why do I need to use the side fill plug?
I know exactly how much fluid it takes (2.665 litres) and I'll be using a funnel with a long gooseneck. So what's the harm in using the top fill plug?
I've included a photo of the too fill plug. It's located beneath the air filter box.