I don't use a torque wrench on those either. If you go too tight with those, they don't snap. they strip the threads, then you have to pull every nut and axle back off to channge it.
I don't use a gasket either just lots of brake clean on the surfaces first. Also, clean out the remaining gear lube at the bottom of the housing. It's that remaining lube that gets on your surface then causes the leak at the bottom.