I appreciate your advice, sir. There is indeed crud behind the blades, and I will be pulling off this throttle body to clean it at some point. I'm out of time before school starts again, but thank you for pointing this out, sir.
I replaced the speed sensor on the differential. I now get a steady reading, instead of an erratic one. However, it now reads 15 mph when I'm doing 60, and between 5 and 10 at around town speeds. OD and TC lockup engaged today, just fine, though. Maybe it helped, and my speedometer isn't reading correctly because of another issue.
