I would and did recently I opened my rear diff at 38k and changed the fluid to 75w-90 Royal Purple, no leaks. In fact my dealer did two oil changes on my Tundra and never replaced the washers, it was stuck to the pan flat, I dint even know it was there after 5 years I purchased 3 new ones should be good for fifteen years.anyone re-used the crush washers on their rear diffs and had any leak problems, or has it been ok? reason im asking is because the dealership here are "fresh out" and have to be ordered!! still not sure why they wouldnt have any 99cent washers in stock?? anyway, think its ok to reuse them?? and i also tried autozone, but they said truck was too new, so they didnt have a listing yet!!