I had to remove the transfer case and transmission on my 2004 F150 in order to replace the flexplate. I need to refill the transfer case (drained prior to removing) and saw that the Ford manual recommends Motorcraft XL-12 which can be had for $15.00 /quart at the dealer . . . . XL-12 is hard to find anywhere else. The parts guy at one of the dealers looked it up and said to use Mercon V ATF fluid. So should I use the XL-12 or the ATF fluid??

JRR
2004 F150 5.4L 4WD Screw
2008 F150 5.4L 4WD Screw

 

Any Mercon V compatible ATF is fine, I'd personally use a synthetic.

 

Thanks - Do I need to worry about any residual fluid still in the transfer case? I guess I could ensure it was completely drained before I re-installed it.

JRR
2004 F150 5.4L 4WD Screw
2008 F150 5.4L 4WD Screw

 

Transfer case is far from critical - just drain it till it stops dripping.

 

Any fully synthetic ATF meeting Mercon V specs is an acceptable fluid.

 

It doesn't even have to be fully synthetic.

 

My 02 Transfer Case is supposed to have Mercon, not Mercon V according to the owner's manual. I'm not sure why Ford would recommend Mercon for the Transfer case and Mercon V for the trans. Since the trans can leak Mercon V into the transfer case, I can't imagine it would make much difference to put Mercon V in the transfer case.

 

Mercon V is the back spec for your TC.

 

helpful here.

 

Change your TC Oil for the recommended XL-12 if you use Mercon V it may damage / explode your TC. Check the opinion fo ForTech Makuloco