Are you talking about the slightly convex metal slug which is driven into hole of the spindle where the end of the kinkpin is located?
No Sir. Your question made me do my DD. I discovered what I'm talking about is the kingpin thrust bearing as shown in fig. 2. Well crap.
In my weak defense my last experience with kingpins was about 50 years ago and then it was on VW sedans. They did have a dust seal at the bottom of the kingpin.
