So, I replaced my check valve with the supposedly improved one a few weeks ago but haven't really used 4WD.

This morning I came across a couple sketchy roads so I put it in 4WD, then disengaged it as I was pulling into the parking lot at work.

Well, it sounded like the 4WD did not disengage. Didn't sound like was grinding, it was almost more like a dragging brake pad or something, just a weird sound, and was worse when I turned the wheel. When I backed up it seemed to go away.

Did the check valve fix not work?

I don't know, of course, your weather conditions, but could there have been a build up of ice/snow somewhere?

I get the same noise, intermittently, more so when the wheels are turned, so I'd say in my not-so-professional opinion that no, the check valve replacement did not fix your issue. I'd look into the solenoid and IWEs.

-John

Where is the solenoid located?

Also where does this fall as far as warranty is concerned? Truck only has 26K on it.

Under the hood by the brake booster

IIRC, it's got the infamous check valve connected to it via hose, so it should be fairly easy to find.

-John

that is correct

Its covered by warranty, IF they can reproduce the issue. I fought with them for a year before they fixed it, problem is they only fixed the check valve and refuse to fix the the damage done to the hub or IWE. Do yourself a favor and just fix it ASAP out of pocket and save yourself the hassle of trying to deal with the service dept.

Here ya go, follow the line off the checkvalve, fastens to one side of the solenoid.
https://lh3.googleusercontent.com/4Z...=w1011-h758-no