Hello, I think this might be a shifter fork issue but I wanted a second opinion.
I have a 2006 hummer h3 with a 3.5 engine, 5spd transmission and a 4:1 transfer case swap. Borg warner 4494 that was purchased as rebuilt.
Was driving it for about 6 months after swapping the transfer case in.
Had a complete loss of power to the wheels.
unable to get the vehicle to move in any gear.
I put it in 4 Low (lock) and the vehicle moves. I then put it back in 4 High (no lock) and the vehicle moves normally, for about 150 ft and then there is a soft clink and then no power to the wheels.
If I then put it in 4 H (lock) it still doesn't move.
I was able to limp it back home (was almost home, 1/2 mile distance).
I then put the parking brake on and put it in gear and release the clutch. vehicle doesn't move. The driveshafts aren't spinning either. I was trying to check if there was a disconnect in the axles somewhere.
the behavior is that the transfer case seems to be in neutral but the light isn't lit.
My next course of action is to get the transfer case in 4 High (no lock) and then disconnect the encoder motor.
Then see if the transfer case stays connected. hopefully this will isolate the problem to either in the transfer case or possibly an issue with the encoding motor or circuitry.
Thank you for your patience and assistance.
Any clarification to my issue or approach to resolving it is appriciated.

 

Sounds like a good diagnostic plan to isolate the Tcase from the encoder.

 

I did have a question for anyone who has taken one of these apart. Is the rotational shaft that moves the shifter fork spring loaded by position. So if the shifter is in high, high lock, or low lock, does it stay in that position if the encoder motor is removed. Can I completely remove the encoder motor from the shaft and should it stay in that range selection.
I am hesitant to point directly to the shift fork, because I can still switch between high unlock and low lock. It may still be wore out and just resetting itself and snapping back onto the ring. Is there anything that the computer would be doing to pop it out of 4high unlock. I don't get a neutral light when it happens.

 

H3 T Cases have two forks. The "Plastic Fork" issue is the fork that shifts between Hi a Hi Lock, the other shifts between hi and low while staying in lock.

I do believe the encoder motor should be removed and not actuated while out of the vehicle as the T Case will not shift unless the motor turns the square shaft of the T Case, or you use a tool (pliers etc...) yourself to turn it.