It's a low pitched hum that seems to be coming from the front end at slower speeds. Hard to describe but it almost sounds like something rubbing but the pitch does not change at different speeds. Doesn't matter if I'm breaking, accelerating or coasting, going straight or turning, in 2 or 4WD and I can feel it faintly in the steering wheel. The other strange thing is it seems to only happen when the temps are 40 degrees or less and it goes way in the summer months. I'm @ 48K miles on original 20 inch Good Year Wranglers and they appear to have tread life left in them, I had them rotated with no change.

Thoughts?

 

IWE issue.

 

Thanks. Was thinking since there is no change in 2W or 4WD that IWE was not the issue. Am I mistaken?

 

Mine does the same thing. Here's a really good video.

Full-Length Repair - Ford F150 Four Wheel Drive 4WD 4X4 Vacuum Hub Actuator - IWE - Bing video

 

Thanks for that and interesting he said it happens when cold...Thing is with mine, it's not a ratcheting sound it's a hum... Same with you??

 

Yeah, it's like a constant grinding and I notice it more if the wheel turns to the left or to the right. I thought it was the tires, so I replaced the tires and it still didn't fix it.

I replaced the solenoid and check valve assembly and I'm getting really good vacuum there, so the only other thing it could be are the actuators. Mine has 129,000 miles, so it's probably about time and it seems like a relatively cheap fix.

 

Picking up what you're laying down but once again mine is a hum, not grinding or ratcheting. Do you think this can still be my issue?

 

Picking up what you're laying down but once again mine is a hum, not grinding or ratcheting. Do you think this can still be my issue?

 

In my experience, IWEs grind, bearings hum, that is unless they are totally gone.
Gerry, has the dealer done any work relating to the IWEs, like pulling the vacuum source hose? At any rate, with the 4A transfer case, you are always feeding a small amount of power to the front whether you are in 2H, 4A, or 4H.
Now I'm not saying it's the front pinion bearing, but it wouldn't hurt to slither under and see if the front drive shaft where it enters the diff doesn't have some radial movement in it. There are cases where that bearing goes south, and starts making noise.
How about your CV boots/joints, are they good?

 

Mine is doing this all of a sudden now too.. Sounds like the LH side only... The hum for me does get louder as I increase speed.. I can definitely feel it in the steering wheel and even the throttle pedal. Also only happens when its cold... usually around the -10°C mark or colder.. Weird thing is as soon as I stop and then start moving again it goes away...

It's going into the dealer on Monday for the harsh shifting issue.. Might have them look into this as well although I dont think they are going to be able to replicate the issue as we are finally starting to see signs of spring here with some warmer temps.