tcruz0004

Thanks for that advice. That is exactly the situation. I did apply some multi-purpose cement to the area for a seal, and I don't plan on doing any rough 4X4 until I get it fixed. But you are correct, they don't create a vacuum seal as I tested the IWE and it works and holds vacuum fine. I'll be moving and maybe my next hobby shop will have a tool I can remove it with. It seems pretty stable though and fine to operate. With two bolts and the pressure from the half shaft it doesn't seem like it's going anywhere soon, and definitely not while in 2WD.

VTX1800N1

Consider the forces on the IWE applied by the half shaft when at full steering lock left/right and suspension extension/compression. Most of that force is handled by the bearings in the hub, but the IWE is affected also. Just be careful with it until you get the bolt replaced.

hardline

Been troubleshooting driveline issues and noticed this. If in 2WD, both IWEs will disengage and I can spin each wheel freely without the halfshaft turning. However, when I lift up the vehicle, and put it into drive, the front driveshaft and halfshafts turn in time with the rear driveshaft.

Vehicle 2003 Expedition (Same 4WD system as 2004 + F150s)

VTX1800N1

That sounds like a problem with the clutch inside the transfer case. Have you checked the fluid? Are they just turning when off the ground or is power actually being transferred to the front driveshaft?

hardline

If I unplug the vacuum line from the IWE solenoid, it transfers power. I am unable to stop the wheels rotating, and will make obvious tracks in gravel as if it were in 4A. I do not get driveline bind though, so there is at least some slippage going on. In 4H I do get bind, so the clutch does fully apply, it just looks like it does not fully unapply. Fluid is a moderately dark red. Was flushed and refilled when I replaced the transmission in December 2015. Used Dex 3 to fill the transfer case and Mercon LV to fill the transmission and torque converter. Transmission fluid is still bright pink, so there is some accelerated wear in the transfer case, which is expected given the symptoms and explanation of possible failure mode. Still averaging 18 MPG so I'm not too worried about excessive load on the system, but will probably replace the transfer case in the spring, as winter is upon me (it is 17F out right now)

VTX1800N1

Ford did change the specification for fluid to Ford Transfer Case fluid. I've not seen it offered anywhere other than the dealer.

EDIT: It's in Amazon now: https://www.amazon.com/Genuine-Ford-.../dp/B001H1K6TQ

hardline

I'm not sure though if fluid would be the cause of this, as the clutch pack is controlled by a solenoid, much in the same manner as the air conditioning compressor clutch is.

VTX1800N1

It may be that it's not releasing entirely. It's certainly not fully engaged with the symptoms you describe either. How many miles on the truck?

STingray1300

VTX, you are obviously well acquainted with the IWE system, so maybe you can point me in the right direction.

47,000 miles on my FX4. Been hard-core wheeling (but I treat the truck with respect, i.e. no thrashing). Just last week I headed up a dirt trail, and decided I wanted 4wd so as not to chew up the trail. So, I'm on a bit of an incline already. I switch to 4-Lo. When I get to a fairly steep part, the left front starts clanking. Each clank made the truck jerk as if gears were stripping. This happened all the way up to the top, maybe a 1/4 mile.

So is there a condition where the actuator would not engage completely, causing this gear jumping sound? (the iwe spring?)

Appreciate your insights!

VTX1800N1

Replied to your PM. I see you found this thread. Best bet is to run through the tests at the beginning of this thread.