4WD transfer case or tranny broken

[FiatBen]

While attempting to fix a problem with the truck randomly shifting into 4WD, I think I broke it.

I pulled the encoder motor, front driveshaft, front actuator to test the motors. I believe I failed to align the encoder motor and transfer case to neutral when I put things back together. When I started the truck and engaged the shift selector (selector was in neutral at the time) there was a disturbingly loud slamming noise and it jumped into 4WL. Now, there is a horrible noise in Park, no noise in Neutral, and the truck will not engage either Reverse or Drive. Any idea what I broke? I don't mind changing out transfer cases if that's the solution, but I'm not skilled enough to pull/replace the tranny. Anyone else have a similar experience or a good guess as to what I've done and whether it's repairable? TIA
'04 XL SLE w/ 5.3 and the 4:60E, 252K miles

 

[Fless]

What make, year, and model?

@rockola1971 for comment

Pull the encoder motor off and manually shift the transfer case into 2hi. Leave the encoder motor off (strap the wire harness away from the driveshaft) and see if the noises go away.

Then line up the encoder motor correctly. I asked about what year because of the differences in the shift shaft (two flats vs splined).

 

[FiatBen]

My bad, neglected to spec the truck, '04 XL SLE w/ 5.3 and the 4:60E, 257K miles on it. Shift shaft is splined. With the encoder off, and trying to engage 2H, still a rattling noise in park and nothing else; quiet in neutral, not engaging reverse or drive gears.

 

[Fless]

Have you manually shifted the transfer case using something on the splined shaft?