hi all, i have an 06 150screw, 5.4, 4x4, 34000 miles.... well, i was out of town last week, and a friend borrowed the truck.... it snowed a bit, so they were using the 4wd. well, when i returned, i drove down the road, popped it into 2wd, and got the famous "grind". sounded like it was on the driver side, so when i got home i checked the IWE's. sure enough, the driver side was staying locked in.
at first, i could get it to free up with a blow drier to warm it up (our temp has been between -2 and 10). so i thought it haybe had some ice inside of it. then today i took it apart and didnt find anything obvious. i verified the operation of the IWE with the engine running, and it is compressing and extending when the vacuum is applid/removed. so, i put fresh grease in it, replaced the hub o-ring, and put it all back together.
i tested it as i was driving home, and still no different !!! ARRGGGHHHH!!! well, when i got home i decided to look at the passenger side IWE also (which was completely fine 2 days ago)... well, with the engine idling in 2wd, i can pull off the vacuum line to lock the IWE, then re attach it, and try to spin the axle. i can hear a slight grinding even then just by spinning it by hand (both side do the same).
so, i went to the dealer and bought a new solenoid (mine was the "old" style, and did have some ice/water on it). well, i put the new solenoid on, blew out the lines with air, and all is still the same......
AM I MISSING SOMETHING HERE ???? i wouldnt think that both of the IWE actuators would go bad at the same time. when i had the driver IWE apart, i compressed it by hand, and then plugged the vacuum port with my finger, and it stayed compressed, so i would assume that it is fine and doesnt have any holes.
they almost act as though they are trying to dis-engage, but arent quite pulling far enough. if i get a vacuum gauge, how much should i be able to read at the inlet to the solenoid? im wondering if i am losing it somewhere.
luckily, right now we are getting a bunch more snow, so i have to use 4wd anyhow, but i would like to get this figured out soon!

Thanks for all of your input.

 

The default position is locked so maybe something in the ECU.

I'm not tot familiar with it but maybe you could unhook the battery for a while to reset it.

 

its not likely that the ECU has anything to do with it.... the solenoid is working just fine. i can verify that by checking for vacuum at the hoses where they connect to the hub, and then hit the switch to 4wd, and i lose the vacuum, as designed. im wondering if i either just dont have enough vacuum, am losing vacuum somewhere, or is the IWE's are coiincendentally bad at the same time.

 

Yeah, it looked you had it covered so it was just a shot in the dark.