the 4 Hi and low lock is not engaging on my 06 hummer h3. the light on buttons goes on, I hear a click from transfer case but the differental does not lock. the awd works okay. any idea what the problem can be?

thanks in advance.

 

could be broken tcase shift fork. i think 06 used plastic, lots of failures

 

Wait, you are talking about transfer case and locking differential issues. 2 different than animals. Please explain.

 

i guess hes talking of the t case diff not locking

 

OK, try this first before you throw possible unneeded $ at it.
Cycle between 4hi unlocked to 4hi locked to 4 low locked about 4 or 5 times.
Sometimes people never shift between them and the actuator gets "lazy" for a lack of a better word.
If you can get into 4low and back to 4 HI unlocked the best isn't a Tcase shift fork issue.