A railroad may not place or continue in service a car, if the car has a plain bearing-
(a) That is missing, cracked, or broken;(b) On which the bearing liner- (1) Is loose; or(2) Has a broken out piece; or(c) That shows signs of having been overheated, as evidenced by-(1) Melted babbitt;(2) Smoke from hot oil; or(3) Journal surface damage.