(a) Measurement of Wear or Looseness. Except as set forth in (e) and (f) of this section, any determination that a ball joint is worn or loose shall be made with an instrument specifically designed and manufactured for measurement of ball joint wear or looseness.

(b) Care and Use of Instrument. The instrument required by (a) of this section shall be used, calibrated, and maintained in accordance with the instructions issued by its manufacturer. The manufacturer shall be the original equipment manufacturer or a manufacturer who is generally known within the automotive repair industry as a supplier of such instruments.

(c) Accuracy of Measurement. The measurement of wear or looseness of a ball joint shall be stated in thousandths of an inch (.001) or in millimeters, whichever is appropriate to the vehicle and to the specifications of the original equipment manufacturer or of the replacement parts manufacturer.

(d) Invoice Requirements. If a ball joint is sold and installed, the degree of wear or looseness of the ball joint being replaced must be recorded on the customer's invoice in accordance with (c) of this section. The maximum allowable wear or looseness permitted by the original equipment manufacturer or by the replacement parts manufacturer must be stated.

(e) Measurement of Wear-Indicating Ball Joints. If a ball joint is equipped with an integral means of measuring wear or looseness, such measurement shall be made and reported in accordance with the manufacturer's directions.

(f) Adjustment of Mechanically Adjustable Ball Joints. A ball joint that has been manufactured with a means of manual adjustment to compensate for wear shall be adjusted in accordance with the instructions of the manufacturer.