I guess nobody else has read that. You might have gotten some old stock from before they converted to Mercon V. Many people use it in their transfer case without issues. I'm using Mobil 1 Synthetic ATF spec'd for Mercon and Mercon V in my transfer case, no problems.

 

I ended up using it after I called the parts counter and then customer care. It is still listed on their data sheet as "do not use in transfer case". Pointed it out to the dealer and customer care. Dealer said that is what they use so I questioned if their was anything in the tsb re: using it in the transfer case and he said no.

Customer care put me on hold after I asked what fluid to use, she went to my owner manual and came back and told me what it says to use......MERCON, I asked and where do I get MERCON? She replied "from the dealer". So I stated to her that it has been discontinued. Put me on hold again, said MERCON V has replaced MERCON, I referred her to the data sheet online and asked her what it said in regards to transfer cases. She then told me they are not a technical dept. and referred me to the dealer, I repeated the whole situation to her, asked if their was anything anywhere from Ford or Motorcraft in writing that states it is o.k to use? She said no.

I asked.... since Ford is so willing to deny warranty for improper fluids who is going to pay for a new transfer case? and she put me on hold. Came back again and suggested I go to Napa Auto Parts and get an ATF that meets the MERCON specs. SO how do I find the MERCON specs? It has been discontinued and their are no specs listed from the manufacturer. Put me on hold again, couldn't take it anymore and hung up.

I believe this is just an oversight on their part but now I have it documented with Ford in case there is ever any issue. Makes me angry that as good as their products are they can be so stupid at times.

 

There's no reason Mercon V couldn't be used. Its not that dissimilar to Mercon, no idea why they say not to use it in transfer cases.

 

Mobile 1 synthetic gear lube is only available in 75w-140 and 75w-90. Ford specs 80w-90 for the front diff.

Is it alright to use the Mobile 1 75w-90 in the front diff?

I would imagine the only difference would be the 75w is slightly more viscous than the 80w when at room temp. At operating temp they would have the same viscosity, wouldn't they?

 

Yeah, no problem using 75w-90.

 

A few of my vehicles have had leaking rebuilt transfer cases and its a pain to find good used rebuilt transmissions assemblies. any one got any suggestions other than salvage yards?