I recently replaced the altenator in my 1993 Buick Lesabre. The new alternator was tagged with a warning to check my belt tensioner as alternator rear bearing damage may result from a spate of defective GM tensioners. Does anyone have experience with this?
The warning seems to describe a problem were too much tension would be applied. I'm wondering how I can test the accessory belt tension to ensure that it is correct - belt tension appears to be ok, nice and snug. Is there is simple/inexpensive way to check for excessive tension?
The failed alternator did squeak slightly from the rear when turned by hand with no belt connected, which might indicate some rear bearing damage as mentioned by the warning which came with the new alternator. I checked for this. I did not notice any free play in the shaft, seemed to move smoothly. Perhaps the bearings are a bit worn but serviceable after 70K miles and 10 years. I did add a new belt this summer (GM replacement part), perhaps the tight new belt, with a "sticky" belt tensioner put too much tension on the old alternator? Replacement of the altenator fixed the no charge current to the battery symptom (unless you tapped the alternator housing with a hammer) - leading me to believe it developed worn contactors/brushes.