jeff9366 said:If you call King Kutter I am sure they will give you instructions on how to drain the gearbox.
Personally, I just add 90 weight gear oil when it is low....like once a year.
There is no internal combustion on a mower, unlike a car engine; gear oil seems to lubricate forever.
Someone may contradict me immediately but I have never heard of a rotary mower owner actually CHANGING the oil.
I sell heavy equipment and can say that not changelingthe oil in any gear box can easily cut its life in half. The gear box could still outlive the mower, just depends on design