What other things have you done to your
SideKick? Body Lift, Suspension lift?
It sounds like you were trying to say the transfer
case mount/s were torn or broken, does the case
move about ?
If the mounts are broken and the case moves out
of normal position, the lever might be hitting the
hole in the floor and prevent selecting 2WD
For reference T-case positions are called 2WD (normal)
4WD (next position) neutral (next forward position) and
4WD Low (farthest forward position)
After re-reading your post, I think you might have a
broken shift fork in the T-case, preventing selection
of 4WD and 4WD Low. This is going to require removal
and dissassembly of the T-case to replace the broken
part
Wild