Thanks for the info all. Considering the foot of snow we just got last
night, I let a local Midas shop do the deed for me this time. I hate
working on cars in the cold and snow. (Bad time to try to get it into my
garage - its gridlocked with my wife's camelias in winter storage and my
son's college apartment stuff as he just graduated in mid December). I will
definitely get one of those Sears tensioner tools for the next time, on this
or any other car.
It looks like the old belt was delaminating from a slight misalignment on
the alternator pulley. As the overhanging section of the belt contacted the
lip on the outer side of the pulley, the resultant flexing was causing small
segments of the flat side's outermost lamination to wear off in small
chunks. From the wear pattern, it probably would have completely corrected
itself eventually after shedding all of the topmost lamination. Otherwise,
the belt looked fine.
No indications of abnormal pulley friction or wear.