Bruce, with any part time 4×4 system, the transfer case will always be slightly wound up when locked into 4×4.
Reason being that the front & rear differentials are being locked together in the transfer case.
When turning, all 4 wheels needs to turn at different speeds to complete the turn, but because the front & rear axles are locked together, some wind-up occurs in the transfer case.
Wind-up is when additional load is placed on the internal gears, keeping them meshed tightly together.
Trying to shift the transfer case from 4H or 4L back into 2H, will be difficult, as the additional load on the gears keep the teeth meshed and prevents disengagement.
This is easily remedied by doing the following:
- Keep driving in a straight line, which gives the gears time to release the tension, before shifting to 2H, or
- Reverse in a straight line for a short distance to release the tension on the gears, then shift to 2H.
This same phenomenon happens to the difflock in your axle, and is remedied by driving in an S to allow the wheels to differentiate, thus releasing pressure on the gears, which will let the locker release.
