Pinion Seal, I can spell. 2003 Expy. Started leaking at 140K miles; seal has been replaced twice by a local independent shop. First seal was replaced in October last but started leaking again this past January. Second seal replace under warranty about two weeks back and leaking again but not as bad. I suspect the seal is not leaking at the lip but at the outside between the seal "shell" and the bore. Is this a common issue? What is the cure? RTV sealant? Doesn't seem like that would last long. Suggestions appreciated.