Answer:
I help engines spin and pants stay up.
To cross the water I'm the way. For water I'm above I touch it not and truth to say I neither swim nor move.
If you lose one of me, you are upset, bewildered, and perplexed. If you lose two of me, you are blissfully unaware. What am I?
Brown I am and much admired; many horses have I tried; tire a horse and worry a man; tell me this riddle if you can.
I have thirteen hearts but no body or soul.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.