I was under my truck today, greasing the rear driveshaft u joints, when I looked at where the pinion yoke meets the pumpkin. I'm seeing a nice gap between the two, far enough apart to see the shiny surfaces inside, and the pumpkin is leaking from there as well. I found a socket big enough for the pinion nut, but I can't tighten it up any. I can loosen it, but that's it. I just had the yoke and seal installed a year ago. Any idea what happened, or what the fix might be? it's a bone stock 87 with open diffs if that matters. Thanks, Tom.