DiscoDan, I had same problem, if the compressor runs for a long time (longer than it should) it is probably an O ring seal in the actuator in the diff. If the compressor only runs for normal time, check that your diff breather is not blocked, remove the diff end spud and blow it out. My diff breather was blocked and oil was coming out the vent on the compressor, with the smell of oil. Since clearing the blocked breather, no more oil or smells, Regards Frank.

