How much do you charge to service the differentials on an Outback?

I just paid $109 for an oil change and tire rotation

Kurt, This doesn't speak to your question about price but when deciding where to take the Outback, you may want to consider going to Subaru Orange Coast. I've worked with both dealerships and my experience with Orange Coast was much better. Craig

Labor rates in SoCal are closer to $125hr than $25. So figure at least $350-$400 in labor if it's a 3 hour job.

Most dealerships charge you labor and product cost. It usually a 3 hour job at $25 a hour. So, you are looking at $75+ plus product cost, and before taxes. It is cheaper to do it yourself.