I had a very reputable mechanic change my front diff seal last month. He inspected the yolk for any imperfections as I asked him. I even had a brand new yolk in the box if he needed it. Original shaft was fine with no need to replace with the new one. Problem is, its leaking once again from the seal! Just to clarify, the leak is not from the cover gasket. The Lube Locker I installed is sealing tight. Another Jeeper said that it is a common problem in the D30 and you just have to check your fluid often, and live with it. Is the case? Just doesn't sound right.