Underwhere

I've read the "Everything you need to know" thread but I can't seem to figure things out. I was hoping some of the experts could chime in.

• When I bought my used truck last month, 4wd seemed to be working fine.
  
• During inspection they told me that the 4wd actuators looked like hell so I replaced both the actuators with new ones.
  
• 3 days ago I got stuck in the snow and found that the 4hi cluster light lit up but the front wheels did not engage.
  
• Yesterday night I put in a new IWE solenoid and tested the truck. All seemed well. The front wheels spun.
  
• On my 30 mile drive to work, halfway I started to feel a binding/shudder type of contact that radiated from the left front wheel at around 40-60 mph.

Is this the actuator partially engaging and disengaging?


Is there any way to actually test the entire system to know that things are working? Next steps?

VTX1800N1

https://www.f150forum.com/f72/how-di...72/?styleid=14

Underwhere

Thanks.
I had to read that about 4 times but I get it.

I'm not sure my problems are related to that any more though.
I don't hear any sort of grinding noises. I've confirmed tonight that 4wd engages and disengages.

I'm not just wondering what the binding/shuddering is.
It's almost like one of the tires is driving on a small rumble strip.

It's really strange though. If I shut the truck off and stay in 2wd it doesn't happen.
I only get that rumble if I go into 4wd and then disengage it.

VTX1800N1

Do the tests to be sure.

Underwhere

Ended up having a Ford tech take a look at it off hours.
He said one of the check valves was completely clogged with debris.

VTX1800N1

That would do it. Happy you got it figured out.

EBC-150

Yeah it's best to clean out all of the lines and the three check valves if you have had a debris (usually rust) problem.

Underwhere

So...I'm looking for more help.
After getting the truck back from the ford tech, 4wd works but I am still having the same weird rumbling issue.

Tonight I pulled all the lines off on my own, blew compressed air through all of them to make sure they were not clogged and confirmed that all the valves are indeed working.
I made sure when the truck was off that both front wheels were 4wd engaged. When I turned the truck on they both disengaged...and when I turned the ESOF to 4wd they re-engaged successfully.

So here's the problem:
If I start the truck in 2wd there are no issues.
I turn the truck to 4wd and as I get up to speed 40+ I may get a rumble perhaps near the drivers side front axle.
If I turn the truck to 2wd this rumble does NOT go away.
If I shut the truck off even for a second and turn it back on then the rumble goes away.

I don't think this is IWE, IWE Solenoid related.

Is it the transfer case? Any suggestions?