I had a squeal from the alternator belt drive area which died away whhen raising revs above tickover. The bottom of the belt jumped up and down, as if too loose.
Last night I cleaned the belt and wheels thoroughly, replaced and re-tightened. The spring moved under tension when turning the auto-adjustment plate with a 3/8 square drive with some strength. I tightened the belt with the manual eccentric tension wheel so as to free the rod, with aligned holes. The belt had been loose. Examination had told me that the idler bearing was a bit rough, though not terrible, and noted it for replacement.
The belt ran quiet yesterday evening, but returned today at the MOT, and worse at idle. I was told that the symptom of the belt jumping up and down was still there, indicating loose belt, after having mentioned the idler bearing. The mechanic asked me had I tightened the manual adjuster (answer yes). Then he told me he had done several of these auto tensioners, and assured me it was the spring not giving tension, and that was the reason for the jumping bottom stretch of the belt. By the way, he admired the car - the model, the recent work I've done, and said I have a good one. Encouraging words to hear, and he was a good chap. The car passed.
What are your thoughts about this
The tensioner moves OK, I thought. I see nothing odd, Should I test it in another way?
The eccentric tensioner wheel is about halfway to full tension, so I am going to tighten that more, as an experiment to see if the squeal dies.
In any case, I have heard this job to replace the spring and wheel complete is frightening people. I haven't found a post detailing the procedure, although I've heard mention of it. What does it entail, and how should I prepare myself?
