What state is the malfunctioning tensioner in ? If it is in a state that it is loose and wont let the regular size belt on, I may have an easier solution. Get a longer belt. The belt I have used and works great is Dayco Poly Cog, 5060915, 6PK2325. What you do is loosen the top bolt on the alternator, remove the bottom bolt, put the belt on and push the alternator down in place, and finally insert and tighten the bottom bolt, and tighten top bolt too. I could have also used 2320 length but this one is not available, only Bando makes it and only comes stock on one american car. But this one works fine so far on my 87, 260E, and I can tell from the A/C working great.

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Saumil S. Patel