Worn bushing rides will leak at the front of the trans; the failure of a convertor in the "freewheel" mode (never stalls) will suck fuel and not accelerate; if stuck "stalled" it will have awesome acceleration (to a point) and suck fuel. Basically, if the convertor has failed, ugly things will happen, with obvious outward signs. Your car will be sluggish and suck fuel, and won't act properly. What are your symptoms?