[Roadie]

When my right axle seal leaked in my 2000 F150, I replaced it my self. I believe the new seal was around $3.00. I also had to drain and replace the diff lube which came to about another $50. It is a very simple operation and doesn't take long.

Of course you need to clean the brake rotor and replace the brake pads if there is oil on those.

I would also check the axle housing vent to make sure it is relieving the pressure when the axle heats up. If this vent stopped up the new seals would also leak.