Howdy! I am now on this magical IWE carpet ride myself! Huge kudos to xj and everyone else's posts I have read.
However I have a question!
Would it be possible for a bad chattering IWE to make a moaning sound while in 4wd? (not the wheel of fortune chatter)
I replaced my check valves and solenoid and trhe chatter went away last night, but returned this morning - pretty sure the passenger IWE that has been wheel-of-fortuning is buggered, and sometimes won't unengage...So when in 4wd, its engaged but it makes a whirring, moaning sound, and does also when I switch to 2wd , but sometimes it unlocks itself and is quiet again (but sometimes chatters).
Going o check all vacuum lines this weekend. IWE's on order from RA. They are (130.00 each here in Calgary!)
If you have a vacuum guage, plug it onto the larger of the two ports on the IWE actuator itself and pump it up to like 15-20 bar. Then just watch it. If the vaccum leakes down on either of them quickly then one of them is definately bad, and more than likely the culprit.
When driving recently I have been noticing more road noise than normal. My truck sounded like it had mud tires on it, especially going up hill or while the truck was under load. I searched and ran across the IWE issue. So, I jacked up one side of the truck, turned the truck on and turned the wheel and sure enough the axle was turning. Jacked up the other side and got the same result. So I'm assuming the hubs aren't disengaging.
I found this thread, read through it and went out a got a vacuum pump & gauge. I Plugged into the driver side IWE and could not get any vacuum to build. I then plugged into the passenger side IWE. Pumped the vacuum to about 20 and the vacuum over the course of about 45 seconds eventually leaks down to 0. I then checked the vacuum line from the solenoid to the wheels and got the same result I got with the passenger side wheel (pumped up to 20 psi leaked down to 0 after about a 45 seconds or so.) How likely is it that both IWE's and the vacuum line could all have gone bad at the same time? Just seems odd to me. I doubled checked the pump and it seems to hold when I hold my finger over the end of it.
Well they are the same age... And have probably been exposed to the same conditions. Are you saying you checked the lines independently, or from the top end while they were connected to the IWEs? If the first, then yes that's a little coincidental.
UPDATE: I ordered and replaced the drivers side IWE only (the one that would not hold any vacuum at all) and that fixed my issue with the hubs engaging. Apparently I was either not getting a good enough seal when vacuum testing the passenger side IWE and vacuum lines or there wasn't enough of a vacuum loss to cause problems.
Thanks for your work to document all this. I have the problem as described, but can't seem to get it fixed. The noise is coming from the passenger side only. I have replaced the solenoid, the actuator and the complete hub assembly. Problem still persists. I now have the solenoid disconnect (by unplugging the electrical cord) just to get around. The problem seems to happen most after high speed driving (55mph on open road) and then when slowing down (say exit ramp) almost like the vacuum is lost as I slow down.
Thanks to the original poster of this thread, you helped me get a better grasp on how the system works.
I am an experienced mechanic and had the infamous grinding on the drivers side under a load. Ordered 2 new actuators off Amazon for $65 each. They seem good quality and same mfr as the $180 actuator...lol.
A word of caution when installing the actuator that I didnt see mentioned in this thread (or I missed it)....when you put the new actuator on with the 3 small bolts, be sure the splines "mesh" with the hub splines.... Just a little wiggle as you press the Actuator in so it fully seats without forcing it.
And most importantly, when inserting the axle shaft through the actuator, rotate it (the axle shaft) back and forth just a little as you tighten the 13mm shaft retainer nut.
The first one I did the splines were "in line" rather than meshing and I cracked the plastic portion of the actuator as I tightened the nut. So just a heads up.....make sure everything meshes and "feels" right as you tighten the axle nut.
I still have the grinding so there has to be a vacuum leak.....have replaced the solenoid but will replace again as it seems to be a high failure rate part....and they are cheap! Have check valves and vacuum reservoir on order.
I love the truck but this system is getting frustrating.
I replaced both of my actuators a few months ago and im again getting a noise from the front pass side. This time when i put it in 4wd the noise gets even worse? When in 2wd i only hear the noise on deceleration around 25mph when im starting to hit the brakes, but when i flip it to 4wd the noise gets worse and sounds like marbles in a tin coffee can? So its like it dosnt have enough vacuum to disengage the hub but cant release enough to engage the hub??
I replaced both actuators two months ago and my grinding went away. Now last week i noticed when coming to a stop a very slight whine from the pass. front. Before work the other day i went under and pulled the vac line off to check it for blockage. After reinstalling the hose i noticed on my way to work no more noise, then on the way home it was back again? So the next day i opened the hood and unhooked the vac line from the first check valve and rehooked it and again no noise on the way to work and i did the same after work and no noise on the way home?
Any idea's, i was going to just replace the solenoid and check valves.
So, after spending a ton of time trying to diagnose the f'n scraping noise in the front end at mild to steep hills or grades at highway speeds, I have found that the IWE had failed and has caused damage to the related wheel hubs. This repair while quite spendy is well worth it as it saved me 50k from buying a new Raptor....