Shipping bolts are installed through the back of the washing machine, and hold the wash tub and basket in place while your washer is being transported. The tub suspension holds the tub correctly in place during the wash, rinse, and spin cycles. If this suspension is damaged during shipping, the tub can shake and move, tilt to one side, or spin incorrectly. This could lead to the suspension or motor failing. When moving your washer, it is suggested that you insert the shipping bolts back into place before moving the machine. This part is also called a washer transit bolt. Remember that this part is sold separately, and to check your model to see how many you require.