Has anyone done the pinion seal (just the seal) on a buick 8.2 rear? My 70 8.2 pinion seal has been leaking for a couple of years. I am sick of seeing wet spot on the diff. I was thinking of doing the "mark the pinion and the nut, count the threads, and put it back on the same place" method. Is this dumb or should I try another method? It has not gotten any worse over the years. Also, if I find that the shaft of worn or grooved, is there a speedi-sleeve that will fix that, or a replacement that is of good quality? Thanks for the advice.