2005 Ram 2500 5.9 diesel - when shifting into 4 wd the tranny sounds like the primary chain is slipping over the teeth, is this possible or is there another reason for this noise. Only makes this nois

is your transfercase electronic or is it the manual lever style? the electronic transfercases are fully synchronized so that you can go from 2H-4H on the fly at speeds in excess of 55MPH, the manual lever style transfercases are not fully synchronized so you either need to be stopped or moving at less than 10MPH to gofrom 2H-4H. if you have the electronic transfercase, you may have a damaged syncronizer. either way no matter which one you have, try at a complete stop (in a parking lot to avoid panic from the noise) to go from 2H-4H and then accelerate, if you get the grinding popping noise, stop, you may have a damaged mode fork, or damaged sprockets. be mindful, if your transfercase locks up it can snap your transmission output shaft, which means $$$$ to repair. personally id pull it apart and check it out.