49 CFR §230.102

1. (a)A box that does not contain visible free oil;
2. (b)A box lid that is missing, broken, or open except to receive servicing;
3. (c)A box containing foreign matter, such as dirt, sand, or coal dust that can reasonably be expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and bearing;
4. (d)A lubricating pad that:
   1. (1)Is missing;
   2. (2)Is not in contact with the journal;
   3. (3)Has a tear extending half the length or width of the pad, or more, except by design;
   4. (4)Shows evidence of having been scorched, burned, or glazed;
   5. (5)Contains decaying or deteriorated fabric that impairs proper lubrication of the pad;
   6. (6)Has an exposed center core (except by design); or
   7. (7)Has metal parts contacting the journal;
5. (e)A plain bearing that:
   1. (1)Is missing, cracked, broken;
   2. (2)Has a bearing liner loose;
   3. (3)Has a broken out piece; or
   4. (4)Has indications of having been overheated, as evidenced by:
      1. (i)Melted babbitt:
      2. (ii)Smoke from hot oil; or
      3. (iii)Journal surface damage; or
6. (f)A plain bearing wedge that:
   1. (1)Is missing, cracked or broken; or
   2. (2)Is not located in its design position.