49 CFR 215.109: Defective plain bearing box: Journal lubrication system.

A railroad may not place or continue in service a car, if the car has a plain bearing box with a lubricating pad that—

(a) Has a tear extending half the length or width of the pad, or more;

(b) Shows evidence of having been scorched, burned, or glazed;

(c) Contains decaying or deteriorated fabric that impairs proper lubrication of the pad;

(d) Has—

(1) An exposed center core (except by design); or

(2) Metal parts contacting the journal; or

(e) Is—

(1) Missing; or

(2) Not in contact with the journal.