Slipping harmonic balancer / crankshaft pulley won't affect actual timing - it will only affect the ability to judge actual timing, if observing the notch on the outer pulley (ie. with timing light, or stationary by comparing to cam pulley mark). The notch won't be where it's supposed to be, but the engine should run fine.

Unless there's an awful lot of slippage, I doubt it will affect water pump or altenator. I've had to replace two crankshaft pulleys, and never had cooling or charging issues.


One more thought on the chirp. My 93 940 squealed a few times after pulling off a highway run. Months later, the water pump shaft seal failed catatrophically. With the belt off, when I rotated the water pump, you could hear a squeak, not the smooth, quiet operation that was suspected. Ari might want to loosen off the water pump belt and try that test.
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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto