I get a metal grinding sound, after the 1700 RPM mark, only when my foot is on the gas, but cannot feel it in the steering wheel. It goes away as soon as I let off of it. I checked the IWE valve, it was water free, the vacuum lines visually seemed fine, and it goes away when put in to 4x4. Once in 4x4, I will hear a clunk when I take a turn, from the same location.

 

It sounds like something in the IWE system. For $25 you can replace the solenoid on the firewall behind the battery. Its fairly cheap and easy to change. Then check the check valves in the vacuum lines. You should only be able to blow through them one way. Then get a vacuum test pump with a gauge and check all the lines on the IWE to see if they hold a vacuum or if it is bleeding off. Check over the lines again really closely for small cracks. If all that fails it may be time to replace the IWE at the hub.

 

I agree with G-Man.
Sounds like IWE

 

Thank you for the quick response. I noticed on the hoses that when I traced them, they seemed to divy off into other components and locations aside from the wheel end. Do you have any recommendation how to proceed from that?

 

I do not. Im pretty sure AFTER the solenoid on the firewall those should only go to the IWEs. I could be wrong though.

 

This is not my drawing and I don't know how accurate it is but might check it to see?

 

If your grinding is only present while you're on the gas. I'd suspect you have a bad diaphragm(s) in the actuators. You'd need to get a vacuum pump to correctly pinpoint.

More RPMs = less vacuum. Vacuum is what keeps the hubs disengaged.

 

Yeah. My truck did that. Went away when I put it in 4 wheel drive. I had a crack in a vac. line. I'd suggest having a shop check the vacuum and use a smoke machine if necessary. I replaced the solenoid for no reason thinking that was the problem. Took it to a shop I trust and it was cheaper than the solenoid.

 

Wow! You either have a great shop or bought your solenoid from the wrong guy!


https://www.napaonline.com/napa/en/p...580/NDP6003580
https://www.amazon.com/Dorman-600-40...0+iwe+solenoid
http://www.rockauto.com/en/moreinfo....433694&jsn=483


All under $30. Ive never gotten my truck in and out of the shop for under $30, not even for an oil change.

 

I bought a motorcraft and it was a couple years ago. I think it was only 30 to have it repaired. Less than half hour of labor and a couple inches vacuum hose. And yes it's a great shop. Couldn't figure out where my Yukon was leaking transmission fluid from and they figured out pan bolts were half a turn loose and didn't charge a thing. Nice to have a shop you can trust.