Hey guys.. I’m not sure if this is the right thread but.. I got a 03 GMC Sierra 2500 hd with a NP261HD. Many months back while in 4wd there was a loud clang followed by a rapid popping coming form the transfer case while engaged but had no issues in 2wd. Finally got around to tearing it apart the other week and found that the range fork and been completely destroyed. Seeing as how I had it tore apart I went ahead and rebuilt the entire t-class, including chain, sprockets, bearing, seals, both shift forks installed a pump saver and a new rear case. Put it back in the truck and tested it. While jacked up 4wd worked perfect, went out to actually use it and I had the same rapid popping sound as before. After driving it for a week I open up the transfer case to see if I could find out what is going on. i found that the range fork has been almost complete destroyed again, it appears to be pushing against one side of the shift collar, While selecting gears by hand everything seems to work as it should. For the life of me I cannot find out what would be causing this issue, any advice would be greatly appreciated.

Thanks, Zach