97 Bravada Vibe and Crunch

Hello, New to this site hope someone can point me in the right direction. Had a howling or high pitch whirring since vehicle was bought. It has 130k on it changed out wheel bearings and added new u-joints and front pads /rotors with one caliper about 1 year ago. Noise remained until last night coming off freeway it started to vibrate heavy. Stopped to check it out in p-lot and it came to a "Crunching Stop" felt like the vehicle was being pulled down. Backed up and drove forward no problem but it was grinding slightly. Drove it 2 blocks to my work lot and it did the crunch stop thing 1 more time. Front end / Rear end or T-case is my question. What is most common failure to begin my search. I must say I smelled hot oil to but not tranny fluid. I am a good wrench but need help sometimes diagnosing. Any help would be appreciated. Thank You, fixdit.

Did you check the tranny fluid level?

Welcome to AF. Do you have the g80 locking diff, this can be an issue with what you describe and it could be the transfer case also, it just requires some diagnostics, see there are any metal filings in the t' case fluid, drain some and see for starters. The awd transfer cases and the diffs were problematic on the Bravada.

Thats good info. I moved him around a little more in the lot with Brother listening and watching from outside. At times it felt like it was loping or slipping from free to siezed. Turned wheel both directions fwd and rev both ways and did get it to lock any direction turned or traveled. I do recall a "bung" noise sometimes when turned sharp and then straightening out when moving from driveway to street like something releasing. Have not heard it in awhile though. Wifes car, dont get much info unless it dont move. Gonna put him up on blocks and slap on the warm gear. Its cold in Minnysoda ya know. Thanks, I will post what I find out or if I need more assistance.