I just got my new gears and posi and and it hums a bit at low speeds. the guy said he did everything correct and what it told him to do for installing the gears. will the gears come out of this during the break in time or is this not good???

Did he add the gm posi additive?

nope don't think so...and I was not aware of this either...

Ya gotta have it......check into it...I bet that will Quiet things down Have a great weekend..