I just changed oil in my 6.0 PSD. I used Rotella T 5w40 purchased from Walmart. I was remembering when I opened the first two jugs the little foil seals where torn away from the jug. There was what looked like some glue on the cap which appeared to have been bonded to the foil seal and therefore lifted the foil seal when I removed the cap. Jugs 3 & 4 did not do this. Has this happened to any one else? I started thinking maybe someone swapped out the Rotella for some cheap stuff. What do you guys think?