Gearbox oil change for deck and one other question

[JOHNTHOMAS]

After a bit more thought, the "technical" comment probably refers to the bottom seal. In order to change that seal you must remove the gear box and that can be a pain. However, it's that seal which is more likely to be the culprit in a catastrophe. It's easier to have an undetected oil leak because of the center pulley and grass clippings and debris obstructing your view.

I wouldn't change the seals unless there was a reason UNLESS you know you won't check them periodically. If it starts looking oily and goopy around the bottom of the gear box check those seals!

I think that's the one he's talking about.