This is the nut that goes on long bolt that attaches the outer end of the rear lower wishbone to the hub. Very often this is seized in place and can be bent during a wheel/kerb interface scenario. The old one is usually removed with an air ratchet gun and a big hammer, which can damage the old nut if it is screwed on in an attempt to protect the end of the thread.
This is also the nut for the horizontal bolt holding the front lower bal joint to the wishbone.
Genuine Mazda part.
B03728091. NM00020.
