The pinion bearing preload is not am exact amount of torque, there
needs to be a specific amount of drag, measured with an inch ounce
torque wrench, this sounds like a big deal but it really isn't, but if you
have doubts, you should find someone locally that can help you, and
the shop you got a quote from, sounds like they quoted the front trans
seal, not the rear one, if not, they are a rip off shop, I would stay away
Wild