sound as a bell

In excellent condition, as in Now that the brakes have been relined, the car is sound as a bell, or The surgery went well and now he's sound as a bell. This simile rests on the assumption that the bell in question is not cracked (which would make it useless). First recorded in 1565, it has survived numerous other similes ( sound as a top or roach or dollar), probably owing to its pun on "sound."