Impact Wrench - Never leave home without one
It may be vintage, it may be excellent quality, but, hate to say it, for most purposes one can get by with one that costs $50 or less from Home Depot or Harbor Freight.
A residential washer would have to be pretty fouled up to need one, but I recall that a little 1/4 butterfly impact wrench with a 12" extension made it possible for one person to pull the tub bolts from the '65 RCA Whirlpool a couple months ago. It was more a matter of reach than needing the impact feature.
They are great for working on cars, though.