When you have a full load.it sucks when your rubber breaks.....
You will get vibration when slowing down with you foot off the pedal or coasting if the carrier bearing is going bad, while accelerating it won't vibrate since there is a load on it. I had mine go bad on me and I asked the service manager a million questions about how and why and it killed some time on our test ride. I had quite a bit of play in mine too and he said that they all have a little play in them after using the truck and it's hard to tell that way but the vibration never lies. I solved the problem by switching to a one piece driveshaft and never looked back.Title pretty much says it all. Does it typically wear out slowly & is there a way to test it to see if it's good or bad?