On front differential what weight of gear lube should I use? Rear diff calls for 75/140 (mobil 1 syn LS) because of towing package, front doesn't give me a weight, so my question is should I use 75/140 or 75/90 cause it's not used as much. Believe the front is a dana 30 and rear is a dana 35. I just picked up mobile 1 cause it had the LS additive in it and is GL5 rated.

 

Pretty much anything will work to be honest because you just need it to lube the internals. I use 80/90.

 

X2 front only requires 80/90 because it is not used all the time like the rear.

 

the front may not be used under pulling power, but its still turning all the time. If your rear has a limited slip, thats why its calling for something different. the front is just an open diff and i'd use 80/90

 

front and back both get 75-90w API-GL5 grad oil
rear tow gets 75-140w sny
trac-lok gets an additive