4 low t.c doesnt work

if i put my jeep in 4 low start it up as soon as i put it in geer it makes a horible striping geer noise. is there anything im doing worng or is ther some thing foin on with my tc. the front driveshaft is currently out but when i tryed puting it in 4 low it was still in. its not like i need 4...