I'm currently replacing the ball joints on my '01 F-350 4x4. I'm replacing the axle and dust seals while I'm at it, but noticed that there are these plastic "spacers" as well. I don't see any mention of them in the factory service manual, nor do I find anyone mentioning them in any online articles that I've found.
Here's a picture of what I'm talking about. Note the loose ring to the left of the U-joint.
Anybody know the part number? I see that mind have some small cracks and it looks like these should be replaced.