Sorry it took so long for me to get back to this thread, out of town.
I did not say it was a TSB, I said it was some kind of DC internal service memo - of which I got the information over on the Carson Dodge site AND my local dealership confirmed that info to me verbally. I have not read the memo myself so I cannot comment on it's validity, but John Holmes is also discussing it on the Carson Dodge site, must be a real memo of some kind.
I directly questioned my local dealership about the costs associated, etc when the time came around for my trucks diffs needing to be done - asked for a quote - my service writer specifically quoted me 75w140 for both diffs and told me about the NEW DC requirement for the 75w140 in all the AAM axles-not only my 2006 but back to the previous years the AAM was used in too. He also gave me two price quotes for the diff fluid - Mopar and Amsoil - both were 75w140. They use both product lines in their serviceing depending on customer preferences. Carson Dodge also uses both product lines from what I gathered in the diff fluid discussions. The discussion about the LS additive come off Carson Dodge's site as well. I do not know about whether it is safe to run the LS with the Amsoil products or if it is even needed, the Amsoil fluid ended the occasional shudder/hop problems I was experiencing without any LS additive. Maybe it has to be added to the Mopar fluids??? I really make NO claims one way or the other, I just re-iterated what I had read, it probably would be better for people to read/interpret and ask questions on the Carson site, better straight out of the mouth that generated the discussions/answers, leaves no room for speculation or interpretation.
As far as someone recommending the WRONG fluids for a transmission, I can see where that could easily happen as there are several trannys being used in the same year trucks. I always do my own homework, ask many questions, check things several times, then the burden falls squarely where it belongs - on me. Our manuals DO have recommendations, sometimes they do not reflect the latest info, sometimes printing errors happen, so again asking many questions over and over will finally get the right answer. My dealership put a couple sticker/pasted in changes in my manual the day I bought my truck, maybe other dealerships don't do what they are supposed to do with these things? My manual also states 75w90 Mopar fluid in the diffs. I had my old diff fluids anaylized when I changed them out to the Amsoil 75w140 basically out of curiosity, since I changed the fluids out the analysis really had no bearing, just info. I am glad I did the analysis as it came back with some real concerns regarding the Mopar 75w90 that was in there and how it really did not hold up well to the period of time our manuals suggest it shoud be used.
CD