According to Chilton's repair manual I can loosen the tensioner by
inserting a 1/2" drive breaker bar into the square hole it the
tensioner. Problem is, there is no square hole, (with a mirror and
flashlight I can see that it is star shaped). Anyone know what tool and
what size is needed. I have a few star type sockets but none this
large. Looks in the neighborhood of 3/8".