Quote Originally Posted by etlsport View Post
sounds like they did leave out the LSD additive. its pretty easy to come by i would get a quart of gear oil 75w-140 and a tube/bottle of the additive, drain a bit of the fluid in the diff and refill with the additive first then top off with the gear oil

also just check to make sure your lug nuts are tight and the tires are properly inflated
x2...

Even if it's not, it won't cost much to eliminate this as the cause, & the coincidental chronology with the service points that direction too.