Rear axle leakage!

[rogergodding]

So I thought that my rear wheel brake cylinders were leaking, turns out that grease is leaking into the brake drums from the axles on both sides. Looking for a good shop in the DFW area to rebuild the rear end and put a posi unit in it. Any suggestions would be great! Also, I thought it was the brakes because my pedal has been slowly going to the floor while sitting at red lights etc..... Master cylinder??