This is a Timken seal, what else could be questionable in this case? If you're replacing this, you've probably fiddled with the left (driver's side) axle shaft for one reason or another. My original Spicer seal, almost 30 years old, disappeared when I rebuilt the D35 IFS spindles and knuckles. The rubber portion of the seal which is fused/bonded to the tapered metal inner lip has separated from the metal causing transmission oil to leak out. Of course, this probably happened when I put the axle