bravada keeps breaking

this will be the third time that i have had to replace the adapter between the transmission and the transfer case on my friends 98 bravada. it keeps craking on the transfer case side. the adapter is where the the transmission mount is located so i doubt it is turning. the bravada has smar
trac. is it possible that when the awd/4wd is engaged it twists the transfer case. i know i have been fixing the symptom but i cant find the real problem. if anyone hase any ideas on this i would sure appreciate the input before i have to do this again in two monthes

It's likely a constantly engaged AWD could break parts including the transfer case of a 1998 Bravada.
You might get a factory service manual, rebuild the transfer case back to factory specs then reinstall.