Loose Pinion Flange on 2002 FX4
I'm in the process of doing an engine swap and was working on dropping the transmission and t-case last night. I pulled the rear drive shaft off and the rear pinion flange is really loose. The shaft and nut didn't seem to be wobbling at all, just the flange. (i've never driven the truck, i bought it with a bad engine) the truck has 160,000 miles. Just wondering what to do. Should i try to tighten the pinion nut? Does this sound like a bad pinion bearing? Any input would be greatly appreciated. Thanks in advance.