So as winter is coming and being in the mountains in an isolated community sometimes 4x4 can be a great help. However i found that mine doesn't seem to be working... I press the button and the lights say 4x4 has engaged, but there doesnt feel to be any power going to the front wheels (rwd spin out up a rocky dirt hill, and can do a brake stand with the rear wheels only)

So... where would i start in trying to diagnose this?
I press the button, hear an audible click and then nothing.

Any suggestions would be greatly appreciated.

Could it be Vaccume lines, Axle, Transfer Case, Switch... and if you could.. would you be able to vaguely tell me where it is i am looking for ^.^

 

If it shows its in 4x4 then its probably just the front axle thats not engaging. Do you hear and audible clunk from under vehicle? Try it with the engine of and just key on, open your door and lean down and listen for a click or clunk sound when you select back and forth between 2 or 4wd. You could try shifting to 4lo and see if your 2wd is acting like low range, then you would know for sure that the T-Case is shifting and the front axle is not. If you are hearing the transfer case shift then its the front axle thats not locking in, this can be caused by a couple things, the vacuum switch on top of the transfer case, any of the vacuum lines connected to that switch, the front differential actuator or damged parts inside the front axle.

The front axle actuator is under the battery, it relys on vacuum from the switch on the T-Case that is activated when it shifts into 4wd, the vacuum switch needs a good vacuum supply from the engine to make all this happen.
My easy fix for this failure prone system is to mechanically lock the front actuator under the battery into the 4x4 engaged position so that the front axle is locked in all the time, then its just up to the transfer case shift motor to engage and disengage the 4x4, it doesnt hurt anything, there may be some tiny mpg loss but its worth it, ive had mine set up like this for 3 years and no problems.
Any questions let me know.

 

Oooh i hear a clunk from underneath the vehicle. if i have it on i can switch from 2hi to 4hi and it clunks every time. I plan to look at the actuator and t case. just need to find time to do so.... and how would i go about locking the actuator?

 

Its been a while but i think i just wrapped some zip ties around the actuator where the cable connects to it, you just need to compress the actuator and make the zip ties hold it in that position. It would be best to put it in 4x4 before shutting it off and then once you get the battery out and get to the actuator you should raise 1 front wheel so you can spin it and then feel it lock in. Just pulling on the cable til it stops wont always lock it in unless the teeth in the axle happen to be lined up perfectly, basically what im saying is ziptie it tight and then try spinning the front wheel, if the transfer case in 4x4 then you should feel the axle lock in and the wheel will no longer turn, once it locks in you may need to put some more pull on your zipties to make sure it stays fully locked and not right in between, when it locks you may get an extra half inch of travel from the cable.
Hope that helps.