I had my '71 on safety stands yesterday and happened to push against the top of my right rear tire and noticed it moved inward about 1/4" (???). Three months ago it had the same problem and I found the spindle nut was stripped so I installed a new nut and torqued it to the recommended 100 ft/lbs and that took care of the problem. But then yesterday I found it loose again. I advanced the spindle nut two hexes and that removed .015" of the .017" end play. So now I'm wondering why it had loosened in just 3 months of semi-daily usage. I live in the mountains so it sees a lot of side loading when I go around corners at 60 mph so perhaps its the side loading that is causing this.