. . . gentlemen, if I have a LSD-rear differential, do I need to add a friction modifier to the oil if on the bottle it says the oil is for LS Differentials?, or is the oil good enough? For example, on the Castrol and Valvoline, the bottles says the oil is good for LSD's so I didn't put any friction modifier in the diff, should I have?, and if I didn't, what might happen?

 

What kind of LSD is it?

 

. . . an 04 Tundra Limited Slip rear differential. Stock Toyota.

 

what does your owner's manual say? look in the back of the "specifications" section