Hey Guys,
I just came across this thread. I have almost 19k on my 2014 Sierra now. My buddy who builds Jeeps was telling me that you should change the diff fluid every 15k. From what I've read so far here that seems to be the general consensus.
I was looking at using either the Mobile 1 synthetic or the Royal Purple equivalent. My truck does not have the rear locker option that I know of so from what I understand the friction additive shouldn't matter to me correct? I'm siding towards the M1 as I've used their products for years on my old truck and was happy with the results. I know that you do pay more for the Royal Purple name...
