Tranny slip in 2wd only

[Yoda]

I have an 06 Tahoe LT with auto 4wd. For some time now, the truck will give random 'service 4wd', 'stability system disabled' and 'service tire monitor' errors. These almost always go away one the truck has been shut off and restarted. A little while ago, I got error codes for TCC solenoid, shift solenoids, and a slew of others. After spending two days replacing shift solenoids (which were just fine), I traced the problem to a faulty ignition switch (go figure). After replacing the ignition switch, there have been no problems till yesterday. 'Service 4wd' came on and disabled push-button controls until the vehicle was shut off and turned back on. When it came back on, Auto 4wd was illuminated. About 50 miles later, I noticed it and put it back into 2wd. Not long after, the truck started 'clunking' every few seconds going down the highway. Upon funding the nearest gas station, I put the thing in park only to have the truck try and roll away on me! It would not go into park, and reverse just makes a long grinding noise until placed back into neutral or park. Drive still worked, but the tranny (or t-case) would pop into neutral over 3k rpms and cause the engine to rev. I was able to get it home and found that Reverse would actually work if the car was in Auto 4wd, but not 2wd. I'm a little confused, can anyone please help?

 

[BRUTUS_T_HOG]

Sounds like the transfer case is junked