Believe what?
My old man always told me, "tight's tight, too tight's fucked" ambiguous I know but try another washer before you strong arm it and strip the nut/expensive bit[/quote That's one way of putting it!
I tend to use a spanner and go by "feel" (admittedly I'm a fitter by trade); torque wrenches can be rendered inaccurate by fluids / oils on threads, or by rust (torque settings are factory defined using clean, dry threads). Maybe worth trying a new washer though.