Additive needed in rear diff or not?

I have a 2013, 4x4 with rear locker
The shop I was talking to wants to sell me a B&G additive for the rear saying it's needed.
After reading thru different threads it looks like ONLY the NON OEM locked rears need the additives when changing out diff fluids.

Am I correct as I plan to do all the fluids my self
Thanks

 

If you have the rear locker, then you have an open differential that doesn't need the additive. I bought some royal purple gear oil recently and changed my rear differential oil myself. The bottle said it contained the LSD additive already in it. So depending on which type of oil you buy it might already have the additive, which won't hurt your differential, it's just not necessary for your truck.

 

B&G is snake oil. Avoid.

 

What does toyota suggest. Always refer to oem literature if your unsure

 

Maybe you should look for another shop.

 

Nope. No uh-uh