so i know there is a bunch of threads and endless flaming on people who suggest using something other than Diaqueen for their X-cases. But recently i went to the dealership to buy some new oil for my X-case and Rear diff. I asked for the diaqueen and they handed me 3 qts of Royal purple. I was hesitant to just take the stuff and go. I asked if that was OK to put RP in my car and they told me that is what they use to service cars. This was at South Coast, I'm not doing this to bad mouth SC. in fact they have really good service but I was alil worried about the royal purple. They assured me that it would be ok.
BTW i'm using the MT90 and MTL mix for my tranny

 

you need to search in the future

tranny you can run the MT90/MTL mix

xcase and rear diff I'd stick to OEM

Diaqueen LSD Gear Oil (Part # - MZ3775610)

 

I did search, oh believe me i did,
i asked them for the OEM fluids, they handed me the RP and assured me it'd be fine.

 

I know this post is a bit late, but FWIW, I wouldn't do that if I were you. Just stick to OEM for transfer and rear diff.

 

I would not use that oil and I would make a genuine effort to do a search on this site for your question.

 

Just fyi,

I'm about to get my service done at SCM too, and when I asked about their fluids they told me they have Royal Purple for the transfer case and something else for the transmission (i forget). I insisted on Royal Purple for the transmission and Diaqueen for the transfer case and rear diff, and they agreed to it. So I'd say just stick to what you know and insist on it.

 

Don't use that RP junk; a dealership should be ashamed of themselves for substituting that for the genuine OEM fluids. I run the Redline cocktail in the tranny and OEM DiaQueen in the transfer case and rear differential.