I didn't get any vibes when one of mine was failing and even after it finally completely fell out, just a ton of rattling noises.
I knew it was failing, one of the cups was working it's way out, sadly, I was asked to go help recover a friends stuck truck. Made the deal with him told him what was going on and said it most likely wouldn't survive the night.
It didn't, cup came completely out, but still did it's job and ultimately tor up the ears so bad it was not repairable. He knew this and agreed to buy a new shaft for it once his truck was recovered.
Got the job done, got the new axle shaft.