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[polilara]

Once again:

Haynes shows how to prevent Cam Sprocket Rotation by "home made" tool when opening or tightening sprocket bolts. I got a warning not to use that method as sprockets can shatter. Is this a real risk?

Acc. to Haynes cam sprocket bolts have to be reneved. Heard also here that it is not necessary.

I know that I work at my owne risk but I would like to start discussion about these two things once again.

I am lazy (and perhaps stupid) but I would like to use old bolts, home made tool and not take cam covers off. Have you ever heard about engine damage caused by this.

I can find new bolts and take covers off if it is the recommended way to do this.

[LC0112G]

The rule of thumb is that any bolt where the tightening spec is X Nm plus Y degrees should not be re-used.

The reason is that the vast majority of bolts tightened this way will stretch past yield, meaning that they are permanently stretched/deformed - i.e. when you take them out they will be longer than when they first went in. A bolt can only be stretched so far before it shears off, and calculating how much stretch is allowed is a complex process. Therefore, it's best NOT to re-use them, especially if they are in a difficult to get at place, or are safety/failure critical. A secondary consideration is can you be sure how many times have the bolts already been re-used? Each re-use will use up some more of the total available "stretch"

It's true that most of the time you will 'get away with it' re-using bolts, and only you can decide whether it's worth the risk or not. In the words of Dirty Harry - "Do you feel lucky punk - do ya?"

[polilara]

Thanks LC0112G, this is what I thought, like head bolts nowdays. I already ordered new bolts so this is clear. As said I am happy that I was warned about breakig those cam sprocets if rotation is prevented with home made tool from sprocket holes. Found that method Ok for normal  Steel Parts but if these sintered parts can be brittle it is thus best to remove covers as informed. Covers are not leaking at the moment as I recently changed the seals thst is why I would like to skip that extra work. But yes I do it if Haynes way not recommended.

[polilara]

Hello all 2pc of 90573287 still missing, so bank 2 cam sprocket bolts. Found from U.S. but freight is 100 USD TO Finland, can you recommen a market place for these in UK?

[Enceladus]

Try a Saab specialist. The Saab V6 (B308) must use the same bolts. You might strike lucky.

[polilara]

Thanks Enceladus, I do it tomorrow, how about Britain, are those parts still available, have to be a cheaper way to dispatch two bolts. Normal 10×1.5*123 length does not fit as after thread the bolt is only 9mm in diameter so it goes inside the cam. Strength is 10.9 so interesting to turn from ten mm to nine if new bolts wanted.

[Nick W]

Now you know why most of us who have undone cam pulleys just reused the original bolts


The same applies to the suspension bolts that are listed as single use.