Yesterday I checked the rear differential fluid in my Tacoma. When I pulled the plug, the oil seemed pretty foamy/frothy/aerated. I had just drive the truck about 5 miles on the highway prior to pulling the plug, so it wasn't sitting very long. I checked it this morning without having driven in and it was normal without all the bubbles in it. Does this seem like a problem? Doesn't seem right to me and has me a little worried. I would think there should be no air bubbles in it.
2002 Toyota Tacoma 3.4L 4X4
2000 Ford F350 7.3L