np 231 swap

i have a np231 that keeps eating the drive chain and i would like to swap it out with a stronger more reliable one any suggestions on what will work or how hard is it to just rebuild the one i have...

I rebuilt mine with no prior experience. The hardest part was figuring out how to get at the top bolts to take it out! By the way the answer is to lower the transmission down and use an air wrench, extension and swivel!! The NP231 itself is really simple. There is a link to pictures and instructions on the rebuild that I'm sure someone will have handy if you decide to try it! I've been told the NP231 is a very good transfer case.