Is the bolt on a Chevy truck idler pulley threaded backward?

No, the bolt on a Chevy truck idler pulley is not typically threaded backward. Standard right-hand threads are used. If you're encountering a bolt that seems to be threaded backward, there's likely a problem:

* Incorrect bolt: The wrong bolt has been installed.

* Damaged threads: The threads on the bolt or pulley are stripped or damaged.

* Unusual modification: Someone might have made a highly unusual modification.

If you're having trouble removing the bolt, check these possibilities before assuming the threads are reversed. Use the correct size and type of socket or wrench. Penetrating oil can help loosen a stuck bolt.