I took a Chrysler 8 3/4 out of a 1972 w100 truck and put it on my 91 power ram 150 in place of the 9 1/4 that I had burnt up.
I put all new seals in the 8 3/4 and replaced the bearings on the axle shafts.
I
Today I got under the truck to grease the u-joints and I noticed a tiny amount of gear oil on the yoke, and it's not coming from the pinion seal, it's coming from behind the pinion nut.
What does this mean?
I torqued the pinion nut to 240 ft lbs when I put the yoke back on it after installing a new pinion seal, it's a 741 case with open 3.55 gears.

Could the oil be wicking out in the pinion splines. Wait for Kunkel & others that are familiar with this

That could be very possible, it's not the stock yoke, I upgraded to a 1350 series cv shaft on the truck, so I'm running an aftermarket 1350 series yoke on the 8 3/4.
It is a very small amount of oil, at first I thought it was some grease that had gotten warm and melted, but when I smelled it I knew it was gear oil.
I also have it a little over filled because I had to rotate the axle up using some Steele shims to point the pinion up towards the t-case since I'm running the cv shaft.