I am replacing my AC idler pulley on my **** forester. I understand basically how it wo...

I am replacing my AC idler pulley on my **** forester. I understand basically how it works and will be able to change the pulley. After removal however I notice that the long adjuster bolt has * nuts on it up near the top which are not tight against the metal at the top under the adjuster bolt head. I cant seem to figure what good they are doing there? I hope Im explaining this in a manner you understand. It seems to me that these * nuts should be up against and under the bolt head. I wish I could attach a picture. In other words, shouldn't the * snall nuts on the long adjuster bolt be up tight against the metal where the Bolt head is?????? Thanks