Part identification

[jevc]

Hoping someone can help identify this part. It’s some sort of nut retainer. I just replaced both exhaust manifolds for the second time. The first was replaced under warranty at 42,000 miles. Now at 114,000 both sides leaked. I replaced with dp diesel manifolds. They are appear well made and I hope they last the life of the truck. Replacing these was hell. Not sure if I’d do it again myself. Any way when I finally got it all buttoned up I found this retainer on the garage floor. Not sure if it came from the steering shaft which I to move around a bit to install the drivers side or just what it came from. Being a retainer I kinda think it might be important. Any one know what this might be for? It’s small. Probably about 3/4 inch or so