I am a huge advocator of finding the answer by yourself through the search bar, however i cant narrow this down or find somebody with the EXACT same symptoms as me. truck is a 2004 FX4.

had to drive up a steep loose gravel road hunting the other day and needed the 4x4 so as not to tear up up the road in 2wd. flipped the switch while stopped at the base of the hill while stopped, heard a click behind the dash, the 4hi light came on, but the front wheels didnt lock in. tried to put it in 4lo, light came on, but nothing. no clunk like normal. i put it in 2wd, started driving on a dirt road at about 3mph and put it in 4hi, light came on, click behind the dash, and i heard a very quiet grinding sort of noise from what sounded like the front right rotor area. in 2wd this faint grinding goes away.

Basically i've read alot about the iwe/4x4 system, but am not sure where to start troubleshooting.

thanks for the help guys

 

Have the motor in the transfer case checked. If it didn't go into 4lo (using the proper procedure, stopped, in neutral, brakes on), even if it is just the rear wheels, then the TC is not shifting at all.

 

When you put in low range did it drive in low range but just 2wd? there could be a couple different issues. One i believe that there is no hub on the axle shaft by the wheel, they are vacuum operated hubs near the front axle housing. In park try spinning your front drive line in 2wd, than try it in 4wd. If it doesn't spin jack up the front axle so the front tires are off the ground and try to spin the tire, if it spins your the other front tire tire that means your hubs are operating. The other issue could be inside your transfer case, the 4wd engage should be electro-magnetic, in other words when you put it in 4wd a big magnet is turned on and it squeezes a clutch pack that engages the front drive shaft.

 

I had almost the exact same symptoms, and it was the IWE solenoid. When I would put it in 4x4, hi or lo, it would click and the light would come on, but when I started driving the front wheels were not engaged and I was getting a slight grinding noise. I wasn't getting the grinding noise in 2x4 like some folks do. I think the solenoid was about $25 from amazon and took 5 minutes to change, and now it works just fine.

 

When you put in low range did it drive in low range but just 2wd?
-nope, drove the same as 2hi. Ill try and spin the front end like you say and see what happens when i get a chance.

I had almost the exact same symptoms, and it was the IWE solenoid. When I would put it in 4x4, hi or lo, it would click and the light would come on, but when I started driving the front wheels were not engaged and I was getting a slight grinding noise. I wasn't getting the grinding noise in 2x4 like some folks do. I think the solenoid was about $25 from amazon and took 5 minutes to change, and now it works just fine.
-this is what im really hoping it is. Do you know if your truck went into low range when you put it in 4lo?

appreciate the info

 

The low range light came on? If it didn't drive in low range, when put in low range even with the front axle engaged or not it should drive in low range. It sounds like a could be a T-Case issue as far as the low range.

 

I don't think it did, it just drove the same as 2wd. Since your symptoms are pretty much the exact same as mine, I'm almost positive it's your IWE solenoid. Even if its not the solenoid, I would still replace it because it's most likely going to go bad at some point.

 

The IWEs have nothing to do with whether the vehicle goes into low range. They only control the front axle/wheel lockup. If it is not going into low range (very low speed and high engine RPM), the problem is in the TC. In most cases on the TC with ESOF, the problem is with the motor that actually shifts the TC. Either it is not being told to shift or the motor is bad itself.

 

so upon believing that it is likely the motor, my google research has said to first bang on the TC with a hammer (seriously). this can allegedly free up the motor which can get stuck in one position. If this does not work, is there a way of testing if it is indeed the TC motor that is faulty short of replacing it?

regardless i plan on replacing the IWE solenoid after reading all the nightmare problems with it, as my truck still has the original part that came with it in 04. 4x4 for me is something that i rarely need, but when i do i NEED it to work. I cant afford for it to leave me over 100 miles out in the middle of nowhere again because of something stupid like this.

once again, i really appreciate you guys helping me out through this

 

When you put it in low range there is a "plunger" type rod that pulls a "4th piece" out of your planetary gear set, and as king fish said there is a motor that activates thats. I'm not sure but i think the motor is on the back side of the t-case (towards the rear axle) if should just be a few bolts and it pops out

 

I have an '02 Screw 4X4 and am having the same problem. When I switch to 4H, it clicks, the light comes on but no power to the front wheels. When I switch to 4L, again it clicks, light and it is in low range but, no power to the front wheels. Is the IWE solenoid on the fire wall behind the battery?

 

You do not have IWEs. Those are on the 04 up only. Your front wheels engage and disengage at the diff. Do a search in the 97-03 forum. This is a common problem which will end up being an engage solenoid problem, vacuum leak, vacuum motor problem, or shift fork problem.

 

Thank you, Kingfish.

 

replaced the solenoid with a new one, no change. im guessing then it has to be the transfer case motor?

 

Where do I post a question about my vehicle? I have a problem what appears to be a slipping or bucking problem when accelerating?