I need help, I'm trying to identify what my front and rear diffs are, i know my front diff was replaced before i bought it so i cant use the build sheet...
also i want to change the fluid in both diffs but i need to know if i have a LSD, true- Lock diffs, I'm not sure if they are?
and whats the best weight fluid to use and what kind of LSD additive should i use if i have a LSD.

 

all zj's have an lp d30 front axle,even if it was replaced they probably used the same axle(don't think they ever offered it with trak-lok). you have a 97 zj? if its a v8 it has a d44(3.73's) rear,I6 d35(3.55's non tow)..in any case there should be a tag on the diff to tell you what axle it is and if its LSD. you can jack up the jeep and spin one rear tire if the other spins in the same direction its LS(unless clutches are shot..also if you have the 249 t-case put it in N for this)

 

The front has tags and some id number, but the rear diff has no id marks for some reason... what the difference between the c8.25 and the Dana 35?
also where are the id marks on the c8.25?
ALSO i have the 4.0l 6, and a 242 transfer case.

 

zj's (93-98 grands) never came with the 8.25....you have a D35