boomboy26

Hey guys,
I have a 95 cherokee running a np242 transfer case.It started to make a squeeking noise while on a big drive around australia.Then evolved to a almost shearing sound.I removed the front driveshaft and the squeek stoped.Now(without the front d/shaft on)when i put it in full time, it is fine until i give it a rev and then a grounching sound starts.i have had it apart and the chain sits around 1 cm from bottom of casing and all the teeth on the drive gear seem ok by visual inspection. when i put it in part time or 4lo it seems fine aswell just in full time..I also noticed when its in full time only the front yoke side spins not the rear is that normal or does the rear kick in when the front slips or something??Im a keen home mechanic so any advice would be very greatly appreciated.
Luke