Carrier bearing ?
Lately my truck has picked up a rattle underneath that has been getting steadily worse. It only really happens under acceleration. Sound is more of a very fast vibration. From inside it sounds like its coming from underneath the back of the cab.
I've crawled underneath and pulled, pushed, beat on and twisted everything I can find. All I have found is that the carrier bearing has a little bit of play in it; ie., I can shove the driveshaft up and down and get a bit of movement in the middle of the bearing. U-joints all feel fine, no play at all in them. Being carrier bearing illiterate, I just wanted to make sure that there should be no movement inside that bearing before changing it out. Is that a correct assumption?