I bought the grade 8 bolts, and installed this on Bren's Fronty. Of course, it started leaking as soon as I pulled the lower bolts out. put it on anyway, and stopped leaking for couple of days, but then came the drip...drip.... Took it over to Peoria Nissan as they have always been good to me anyway, and the service advisor we use, Brad Ernest had it taken care of under warranty w/o a question. Keeps me bringing my X and her Fronty in cuz he tries to do right by us. So anyway, diff resealed and Shrock ring installed.