Generally this is a symptom of a bad wheel bearing. In order for the oil to get that far, it has to go through the inner seal (in the axle housing), the bearing, and then the outer seal.

Theoretically you need a press to get the bearing off and to get at the outer seal, but there are other ways- like the "slam it on the concrete method" which has always worked well for me. <img border="0" title="" alt="[Big Grin]" src="images/icons/grin.gif" />

'97 4Runner, '06 F350, '86 4Runner, '05 WR450
http://home.4x4wire.com/erik