I had a trailblazer and a scrambler and my buddy had a trailboss that all broke chains and the trailblazer and trailboss also had to have the transmission chain replaced due to making a noise like you described. like it was jumping the gear teeth

 

i allways use silicon lubricant, comes in an aresole can, for my chain. my dealer recomended it and it works really good, all the links move freely

 

you got it !!!
same thing happened on my trail boss this weekend, when got stuck in the mud, when throttle was applyed a loud clicking sound came from the transfer case , the shift lever was shaking back and forth just like it wanted to jump out from the selected forward gear, the wheel did not move , nor the chain, so it is not the chain which is driving the rear wheel.
it is from the transfercase for sure.
I gues same thing could happend when you are braking hard.
a loose chain in the transfercase or the forward -reverse selecting gears are pulling appart.
I never had the transfercase appart yet, so I need to see how the gears are engaging.