I don't think there is an inner seal on the 35, the outer axle bearings are lubed with the oil in the differential.
I'd check and make sure it is diff oil and not a leaking brake cylinder. The leaking brake cylinder is a lot more common. Pull back the rubber boot on the brake cylinder near the bottom, carefully, just a corner and see if some brake fluid flows out. If you just crack the boot on the brake cylinder instead of removing it all the way, it is a lot easier to get back on there.
If it is the seal chances are the axle bearings are worn.