crank pulley- unbalanced?

Question

Hi,A friend and I tried to change my '92 900's crankshaft pulley this weekend. Weended up failing, because we didn't have a 27mm socket shallow enough to getbetween the pulley and the firewall (honestly, I've never even seen one thatshallow- how do people do that?). In the process of reassembling thepulley, there was another problem: we broke one of the 3 10mm bolts that holdsthe AC pulley to the crank pulley. So that bolt is missing the head and about1/2 of the threads. The car runs fine, but I'm concerned about the fact that the crank pulley isnow slightly asymmetrical. Is this imbalance significant enough to worry aboutit damaging the crankshaft?Also, one more thing: the new belts we put on seem much more audible than theold ones-- they make a sort of whistling/whining sound that I didn't hearbefore. Is this indicative of some problem (perhaps belts are too tight)? Or isit maybe because the new belts have teeth on them and the old ones didn't?Thanks for your help.John

Grunff · Accepted Answer

You can buy them, but I cut one down. Very useful thing it is too.

Do you mean the imbalance caused by the broken bolt head? I doubt you have anything to worry about there. But are you driving the AC belt off that pulley? If so, I think that's asking for trouble.

New belts often make a whirring noise, but do check that they're not too tight. A quick spray of belt dressing wouldn't do any harm either.

John B · Answer

Hmm, yes, I am driving the AC belt. It seems to be working fine so far. I'll only need AC for the next couple weeks probably, so maybe I'll just take the belt off then until I can try to change the crank pulley again.

I loosened the AC belt, and I think that decreassed or eliminated the whirring noise (though I didn't test it too thoroughly). Also, I think that having the AC belt as loose as possible will decrease the strain on the 2/3-bolted-on AC pulley.

Anyway, if the AC pulley separated from the crank pulley while driving, what would happen?

John

Grunff · Answer

Depends which direction it flies in ;-)It could cause some damage, or just harmlessly drop away.

John · Answer

Ok. I hate driving around with that risk, but hopefully I'll have a chance to change the crankshaft pulley before anything bad happens.

Of course, this would all be so much easier if the belts were at the front of the engine... why is the Saab 900 engine installed "backwards?" After all, the belts need to be serviced more often than the clutch.

John

Grunff · Answer

I like the layout - none of my 900s have AC, so the belts are all easy to get at.

crank pulley- unbalanced?

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