Any documentaion of this????
Just because a "Dodge dealer says" I'm not going to run out and drop my differential oil and put a non recommended lubricant in there. In my owners manual, as well as my 03 service manual, it says not to use anything but 75-90 synthetic oil in the AAM axles. I've seen no TSB or anything else in writing that says to use the 75-140 synthetic oil in the AAM axles. The old Dana axles, it's specified, the AAM axles; not an approved lubricant. I monitor the temperature in all my gear boxes except the front differential, and I'd be more worried about the NV 5600 than the rear differential. It runs 200 -220 F towing at 65-70 MPH. Rear differential 150-175 not towing and 185-200 towing again 65-70 MPH. Just my . 02. Ken Irwin