Gear oil or engine oil in a Toro DH-170 gearbox ..

[bretonlion]

I have a Toro DH-170 with a TuF Torq g/box .. My apologies for asking this question again .. can I use engine oil 10w-40 in it .. or has it to be gear oil 10w - 40 Thanks ..

 

[StarTech]

15w50 synthetic or 20w50 dino engine oil.