This might sound dumb but I'm so confused i have a 02 ram 4wd and I'm confused about the diff fluid I have a LSD and what do I use

 

80W90 with friction modifier if you just drive it. 70W140 with friction modifier if you tow/haul regularly.

 

Right from the 2002 DR service manual:

 

bit isn’t 80w90 for the front

 

Depends on what you do with it. They are both differentials, they both work exactly the same way. The rear gets more use, as most folks don't use 4x4 very often, so, for the rear, if you use your truck AS a truck, the recommend a slightly different lube.

 

I would add the same type of fluid to the front as to the rear. Weather its 80/90 or 70/140. Safe bet is the 70/140.