Thanks to YouTube i found my issue. I'm experiencing the same exact sound.


Seems to be a IWE / vacuum line issue

 

Now, that's EXACTLY where I would have pointed you if you had removed the belt and said that the noise was still there...........

https://www.f150online.com/forums/ar...then-some.html

 

Thanks again for following up! I just picked up a solenoid from AutoZone and about to install this little guy with an umbrella 😊 In the mean time I'm driving around in 4WD

 

You sure it's the solenoid? Have you done the troubleshooting in the thread I linked?

Driving in 4wd on pavement is NOT advised! You can bind up the front drivetrain when you try to turn corners and cause more damage.

The BEST thing to do is pull the vacuum lines off both IWE's and plug them, leave the transfer case in 2wd till you get it fixed.

 

so i replaced the solenoid w/ umbrella and still didn't get rid of the grinding noise. I read the thread you sent earlier and seems like i need to check the lines and IWE for leaks with a vacuum pump. By removing the vacuum line from the IWE will that prevent making grinding noise for the time being while i try to troubleshoot?

 

Remove the vacuum lines from BOTH IWE's and plug them, the IWE's will remain locked. Leave the transfer case in 2wd and you won't damage anything driving it on pavement. Go drive it - if the noise is gone, you know what to look for, the IWE's are losing vacuum somewhere, use the troubleshooting procedures. If the noise is still there, it's something else or maybe one or both of the IWE's are already damaged.

 

Broken vacuum line by the IWE solenoid possibly causing the intermittent grinding noise at the wheel hub

Took my truck to my friend who owns a Mechanic shop and performed a Vacuum smoke test. Results came out negative but he insisted on doing the old school way of moving the vacuum lines around to listen for any leaks and found this near the IWE solenoid.

 

That will do it.

 

Thanks again GLC for being responsive in this forum....

I'm still hearing a little chatter coming from the wheel hub while driving under load. Perhaps the IWE hub could be on its way out.... At least for now the continuous grinding noise isn't being observed in recent trips.....

 

The chattering is probably indicative of either damage to the IWE or the IWE itself has a vacuum leak. Pull the vacuum line off the IWE and apply vacuum to it and see if it holds. It should not bleed down. It also may have a leaky check valve or vacuum reservoir. Keep troubleshooting, you have the tools and reference.

 

It's a faint chattering sound while under heavy load but I did check the hubs and it didn't bleed down. We tested the lines and it holds vacuum as it should. Perhaps it could be faulty check valves....

 

The chattering under heavy load is most likely insufficient vacuum. That's what the reservoir and check valve is for, to provide enough vacuum under wide open throttle when the engine is not creating any vacuum.

 

Ah thanks for that advice! I was intentionally flooring it to hear if it would grind again. At least under normal driving conditions it's ok.....for now