Persistent Belt Squeal Fixed

[sceh]

I changed the belt on my Yaris and used a part-worn belt from another car. I also changed the water pump. Result? A squeal all the time - hot, cold or wet. I tried WD40 on all the bearings and some belt fluid which made it even worse. I tightened it and loosened it but there was no change.

I then noticed that the belt seemed to be slightly to one side on the lower pulley (the crankshaft). It turned out that the belt was running fine in all the pulleys but was one notch to the right on the lower pulley. I moved it - problem solved. Since this seems to be so easy to get wrong I though I would share it because it could be the source of squeals. I guess it could happen on any of the pulleys quite easily.