I need a new rear drive shaft for my 2015 2500 crewcab 4x4 short bed diesel with automatic. I called my local dealer today to try to get a good part number but sat on hold and just hung up. After doing alot of online looking I'm still confused. Mine is one piece all aluminum all one diameter front to back. There is a sticker on it but no longer able to read what it says. Looking online I keep seeing 3 separate parts numbers. But it seems all the gas and diesel trucks with same bed size and crew cab all use the same shaft ? But there is a steel version ? I don't think 1/2 trucks would be the same but could be since it listed in with 2500 trucks on one shaft but not the other. Trying to buy a used drive shaft online but want the right one. 300 right now fits the budget over 1k for new. Anyone got any insight on the issue ?