Detail: Terracan V6 3.5L auto 2006 model High and low lights appear on the dash and the high/low range does not engage, appears the fre-wheel hubs are also engaged all the time, checked all possible connections for a short/grounding but cannot find anything obvious, what could this problem be,
Solution: Hi, a 6ya Mechanic can help you resolve that issue over the phone in a minute or two. Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck! , When you turn the knob to 4x4 the transfer case will engage then it will also activate the vacuum for the hubs. the truck will kick to a lower gear with transfer case engaged but the hubs are not. thats where the manual hubs come in you will have to lock them in order to spin the wheel. , your problem is probably the front axle solenoid. it is in the center of the truck on the front axle and it is really easy to change. Simply unplug the electrical connector and use a wrench to loosen it. Spin it counter clockwise until it comes out........Manual hubs i believe are not available for this truck but i think there is a aftermarket cable you can buy and install to lock the front diff in. , I had the same thing happen. The automatic locking hubs are faulty, causing one or both hubs to try to engage or disengage onto the front driveshaft. This makes the clicking noise and loud clunking that you hear. You may notice your steering pulling to one side of the road,because one hub is locked in. Replace the automatic hubs with new ones, do not try to fix the old ones. I liked the convience of automatic hubs but replaced mine with manual hubs, there just way more reliable. , Well, the best way is to place the vehicle on a hoist and raise all 4 wheels off the ground and put it in 4WD and see if all the wheels start turning. Another way is to make a really sharp (slow) turn while the unit is in 4 wheel high or 4 wheel low on dry pavement. You should be able to feel the driveline wrap-up caused by the front wheels trying to grab during the hard turn. 4 Low should be easily distinguishable from 4 High as well as 2 Whl when you accelerate and it feels like the transmision is stuck in low gear and the engine starts screaming for mercy at high RPM and you are only doing 30 MPH.