I was flipping thru the pages of my owners manual and touched upon the spec for the transfer case, says MERCON.

For some reason when I changed it several years ago I used the Ford Transfer Case fluid XL-12....trying to think why I used the XL-12????

Is it compatible? Wondering if I should change it out to the now recommended Mercon LV??

Thanks!

 

Ford's crack team of accounts that make a lot of their engineering decisions has a habit of not picking necessary the best, or most correct fluid for things, and just picking the closest thing they already have in a red motorcraft labeled bottle and saying " there , that ought to be good enough".

Ford used to spec the same fluid for the transmissions and transfer case (long time ago now), then they changed transmission fluid but kept the old stiff available as transfer case fluid, then discontinued that so they had to recommend a motorcraft something to put in there.

Lucky transfer cases are pretty simple inside (hence why they last so long even though the fluid is not really filtered and often neglected for decades), so don't stress to much about what you put in there, pretty much any ATF will be okay.

If you really want something that says transfer case fluid on the label, then Valvoline makes a full synthetic transfer case fluid (see amazon link below, you can enlarge the pictures and read the labels in that amazon listing), it even says "Recommend for Ford XL-12" on it, but that statement does not mean it meets the specs for XL-12 , just says "recommended". But it seems to work pretty good, have it in the transfer cases of three Fords, one Dodge, and one jeep at the moment, they haven't broken yet.

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