star69

? we ohm metered both wires from the magnetic clutch. they both go to the gem. there is now power to either wire.

star69

okay, it turns out we are getting a 12v signal for about 4 seconds to the magnetic clutch. there are 2 wires . one wire is a permanent ground to the transfercase and goes to the pcm. the other is a power source that signals the clutch to engage for several seconds. i (i know crude but what do i have to loose at this point) ran a 12v jumper to the clutch. it now
engages and the 4 wheel works until you decelerate and allow slack in the driveline tahn pops out of 4 wheel. This is primarily on slippery snow covered roads. if you do this on dry roads (which you shoulnt) it stays in because of what appears to be excessive drag on the driveline. i already had the transfercase apart and inspected but now i am thinking i may have missed something.

Jack Tacy

Did you figure out what the problem was ? Have same thing going on

Cory Lieberman

I am having the same exact issue I have replaced both hubs both vacuum actuators all vacuum lines tested the iwe vacuum solenoid on the firewall and it is bad but bypassing it gives me the same issue so I was wondering if it could be the front differential gear stripped out perhaps? If anybody has any knowledge on this issue or topic please don't hesitate to message me thank you very much

Jojodapyro

The last reply on this was over 2 years ago.

KJonesy33

If anyone ever found any answers or conclusions on this issue it would still be very helpful. I have an 06 with the same symptoms and unable to diagnose

Shawn Chapman

Did you try replacing the check valve sometimes they slowly leak causing hubs to engage and disengage. I have an issue with my 2010 where I hear the paint can rattle noise on front left but in 2wd the axles does not spin out it in 4wd it spins but my passenger side half shaft spins in both 4ws and 2. I have vacuum to both iwe's so I'm kinda wondering if it's iwe or check valve that keeps passenger side locked and get rattle noise on driver side.

Jmacdaddy64

Mine has the same issue. The IWE is functioning properly. I went as far as replacing the vacuum lines just in case. I jacked it up and engaged 4wd while in park. Put in drive and heard an odd grinding noise from the tc, and front drive shaft wouldn’t spin, but was vibrating. Put back in park, disengaged the re-engaged 4wd and driveshaft then spun in drive. Tried this several times and driveshaft engagement was intermittent. Thought it was the shift motor, so I replaced. No change. Was just stuck in a snow drift and found as I rocked the truck back and forth, if when it came to a stop and I switched out of 4wd then back in, it would engage for a short time. It got me free, but I’m sure it’s not healthy for it. It’s a beat up old work truck, but still runs good. So be nice to figure it out.