Yeah, they're the two bearing s that go on the ball part of the knuckle. Last year I noticed one of the knuckles on my truck was leaking oil, so I decided to tear it down, thinking the oil seal was bad. Got the axle apart, only to find both bearings one the driver side were destroyed. Pieces of it were floating around in the knuckle, and its mostly just luck that I hadn't had the truck in 4wd in a few weeks, or I would've probally done a lot of damage. The wheel was solid, and I really felt no difference in it while driving. After my roll I noticed my knuckles were leaking pretty badly, which I found out was due to me breaking the studs holding on the hysteer and letting the knuckel move which once again destroyed all the bearings. I think this most likely happened before the roll considering the way they looked. Amazingly everything held up till I got back to camp, but one wheel was starting to lean pretty badly.