Using a metal clevis on a metal throttle are if that is what you are doing if a very poor plan as you found out the high vibration at that point will cause the threads to erode and the rolled seam to open imperceptably.

Even worse is the RF noise that will be generated at this point as the clevis pin wears the hole in the throttle arm. Its not a question of if it will cause the loss of your airplane but only when. Never use metal to metal on a throttle arm.

John