What's the correct type and weight lube for the rear differential in my 2004 Dodge Ram 1500. This is a 9.25 sure-grip with 3.55 ratio. The reason I ask is that I've heard the 9.25 is a problem child (design defect). My '96 Ram had the same rear and despite using Mobil One it still smoked the bearings at about 75K. I don't want to go through that again. BTW - The factory fill was changed at 10K when they repaired a bad pinion seal, now she's got 20K. Any comments and/or ideas?