I just got off of nightshift so I'll try to make sense. I just changed all the fluids in my '78 FJ40. It's my understanding that there are seals in the differential. So what fluid lubes the birfield/axle? There must be something because I have some seepage around the trunion felt. There is also a fill plug above each trunion. ( I assume that's what they are). So what lube is added,how much and how do you drain/check it. Stupid question? ???