I found the main lead was snapping just behind the lug - given good-quality gear was being used, the only culprit left was fatigue from vibration. After it left me 150km from home and running just on low-beam and falling main battery power.......steps were taken.I seem to recall two small, soft suspension bushes were found and the mount and alternator modded slightly to fit them. It's been a while, though, as I sold the car in 1992.