So I put in some alloy shafts a while back and while I was at it, threw the superior axle tube seals on. D30 here. I changed the lower ball joints this last week and found that the stock inner seals had leaked and there was diff oil/ grease muck all over the axle shafts as I pulled them out. I excessively greased the shaft putting them in the first time to avoid tearing the inner seal, so I expected grease, just surprised to see the diff fluid out of the pumpkin and mixing.

First step is checking/changing out the diff fluid.

Is a leaky inner seal a big deal as long as I've got the outer sealed?