Rock hard loud noise in 4WD H/L

[door54]

Hard loud noise in 4WD H or L .. under load .. non rhythmatic. 2000 5.4 150K original owner. Mojave desert use only. The problem began in Feb '22 pre running Parker time trials course hit some deep soft stuff and had to power through it and it sounded like large loud rock strikes under front end. WTH? Has always been a solid performer every time I put it in 4WD until now. Now whenever under load in deep sand or gravel..same type of noise. It can be one or two pops...sometimes four to eight. Like a baseball bat on the frame loud. Sand dunes at Hammers was ridiculous...but at the MINT next to nothing...did its job great. Local reputable shop says replace transfer case. Doesn't make sense to me. Any ideas or suggestions would help. Thanks.

 

[Yupster Dog]

@door54
First thing I would check is the transfer case motor. Had some similar stuff happen and it was that little motor not fully shifting. Super easy to drop a new motor in.

 

[Fastcar]

Might be a mount.

 

[door54]

Thanks for the response...spent a good amount of time underneath since this began.. looking for anything on everything. All nuts, bolts, connections, seams, welds in place/intact. Taking a blind stab at this..just by the noise characteristics its sounds like teeth colliding after spinning through a section of missing teeth on a couple of gears. But I will certainly start with the transfer case motor and work that into the resolution
Do you think the potential culprit could be a compromised rack/pinion union up front?