After reading around I think it's an IWE problem. It randomly sounds like i'm dragging metal on the road. I've tested multiple times with switching to 4H as soon as the noise starts and that makes it go away instantly every single time. I called the dealership because the truck is still under warranty and have an appointment for Monday. They said they would probably keep the truck 5-6 days...I thought this was supposed to be a simple vacuum problem? and this will be covered under warranty won't it?

 

I would think it would be covered.

Yes could be a vacuum issue (most likely) or something else like the front diff or TC. If vacuum issue only, then it could be the lines, solenoid, check valve (first suspect) or one/both IWEs (they have seals that can leak also).

 

Did you put a lift or leveling kit on your truck?

 

This has been posted numerous times... there’s a running thread on it actually. I had same issue and it was an easy dealship fix.

 

There is a TSB on this issue - mine had it and the dealer replaced a short piece of vacuum hose and the check valve. East fix.

 

IWE tsb

 

thanks all. no lift. I ordered the check valve and that will be here tomorrow...hopefully that will fix it. If not guess I'll keep the appointment Monday and be without the truck for a week.

 

They fixed mine same day, I’m sure you’re not the first to have the issue. Did they tell you a week?

 

In the meantime while you are waiting, if you have 4A, keep it in 4A so that you aren't grind all the time. If you don't you should be able to pull the plug on the solenoid. This will keep vacuum from being applied so the IWEs will stay engaged. Since the TC isn't engaged, you won't have to worry about dry pavement. You may see a small drop in gas mileage though.

 

yeah they said 5-6 days on the phone
Thanks, I've been running in 4A since it started.