Today I removed my front driveshaft for cleaning painting and universal replacement. So I separated the sliding yoke from the driveshaft so I could clean the old grease from the splines. While cleaning the recess at the base splines at the sliding yoke, I saw some sort of felt packing. I used a pick and removed it which went 360 degrees around the shaft. I'm in the process of obtaining some Toyota repair manuals but currently only have a Haynes Manual. While scoping out the exploded diagram of the drive shaft, I did not see and type of packing. Anyone seen this before? I'm wondering if this factory or a PO addition.