Dana 44 diff fluid

[Comanchekid203]

Hey everyone ! New member here , on my second Comanche now ( 89 4.0 4wd auto) I’ve already done plugs, wires , cap and rotor , oil filter housing seals , new oil pan with gasket , new valve cover gasket , tranny service and new tranny lines . Next on the list is flushing diffs and t case , I’m used to the Dana 30s , but the rear end in this truck is a Dana 44 , and I’m honestly not sure what type of fluid to put in it , anyone else have a Dana 44 with some knowledge of this ? Thank you ! 

[rokinn]

You need to determine whether it is an open diff or a trac lock limited slip (or quite possibly something else).  Trac lock LS needs a friction modifier.  Should be a tag on the back.  If it's not there then you need to open it up and determine what it is.  If you open it up take a pic and someone on here can tell you what it is.

[Pete M]

I do believe it's straight up 80W-90 gear oil and then add in a friction modifier if it's a posi.   

[MiNi Beast]