Last couple of years for original 1354 TransferCase on this 2001 Ford ExST V6~4.0L~SOHC, been using
Valvoline Dex\Merc\MerconLV~FullSyn ATF (1qt or 5qt bottle) from WalMart.
Couple of quarts left in a 5qt bottle on garage shelf now, sharpy marked "For 2001 ExST TransferCase ONLY".
TC seems happy running+shifting 2WHi~4WHi~4WLo without leaks or operating issue.
Did have to replace 4x4 control module & shift motor a couple of years ago, but original TC itself still running good.
To be clear,
use "Dex\Merc\Mercon\MerconLV" compatible ATF in the 1354 TransferCase,
and "MerconV" compatible ATF in the 5r55e Transmission,
do NOT mix these up.
Hope this helps.
D
View attachment 322364