WOW! "Out-of-Your-League" and mine too!
Here's what it sounds like to me though, somehow moving the TC lever is having an effect on the TPS (Throttle Position Sensor, not an uncommon failure at the top of the pedal). It is not uncommon for the tiny wires that goto the OverDrive sw at the end of the Shift Selector to chafe through under the column cover. At first this and draws-down the line associated with the TPS and knock it out (temporally).
Not sure other ways it happens that's connected with the TC but it's where I'd start...
If there's anyway you can get it on a professional scanner (Generic OBD-II scanners don't work on our trucks very well) and monitor the TPS readings while you go into 4WD it would be the quickest way to see if there's a correlation.
Next, I assume you've gone underneath and looked at the Linkage to the TC for evidence of wires it could be hitting? I'm gonna say it's an electrical issue...