NHTSA Complaint #11513149 — 2004 MERCEDES BENZ ML350

OEM jack failed without warning. No injuries but it could have been bad. Car got stuck and spinning wheels dug into a region of hard packed snow over a gravel driveway at my father's house. I was using the jack to lift the wheels out of their holes so I could fill the hole with chunks of wood. To spread the load on the snow the base of the jack was on a roughly 10" long piece of 2x4, which was placed on a roughly 8x10 inch piece of plywood. Jack worked fine for the first 2 wheels. On the 3rd wheel the "thrust washer" that transfers force from the nut that rides on the main screw, to the hinged arm which picks up the car, split in half without warning. This resulted in a sudden and complete failure of the jack, dropping the car back to it's starting position.