11 Bravo

iTrader: (3)

I plan to put in my pulley tomorrow. I didn't order a new bolt for it. Alot of people say you need to have a new bolt, a few say you don't. Exactly why do I need a new one? Does it like, disinegrate when I unbolt it lol!? Or will the old one be fine?

jmX

Some claim the bolt stretches, some think it doesnt. If I recall correctly I compared my used one to my new one and in fact the threads didnt match up implying it had been stretched.

New bolts come with threadlock pre-applied, so if you do for some reason decide to reuse it, at least apply some red locktite.

11 Bravo

iTrader: (3)

Hmmm, thanks. I think I'll go to the dealership tomorrow and see if they have one. Cheap insurance, I guess.

The Derek H

I reused one on my old 99 SS and I heard a terrible belt squeaking noise one day. Got under the car to look at the drive belt by the crank. The bolt wasn't screwed in at all it had backed out. If it wasn't so hard to come off the crank hub I would have lost the whole damn thing <img src="images/icons/wink.gif" border="0"> Get a new one its worth the cash

AAron

alot of the major bolt in our engines are stretch bolt and yes the crank is one of them. im on my 3rd bolt <img src="images/icons/smile.gif" border="0">

McRat

Think about it. Why doesn't a bolt just come loose no matter how tight you get it? There is nothing stopping it except thread to thread friction, and things that are held by friction are vibration sensitive. Take a board and put a quarter on it, and hold it a 30° angle from horz. The quarter sits there unless you shake the board, then it moves.

The reason? The bolt stretching acts like a spring. This keeps vibration from loosening it. Problem is, that the steel they use in bolts is not "spring steel". It loses it's spring after being stretched.

Everyone has noticed that things that have been taken off a car get loose easier than things that have never been removed. This is why.