My 05' F 150 has been in and out of the shop for a intermitant whining or grinding sound that sounds like it is coming from the front of the vehicle area. They are unable to find or reproduce the sound at the dealership. The reason I think it is the transfer case, while the sound was happening, I reached over and flip on the 4H and the sound went away. Any ideas on what it might be?

 

have you looked into the center axle disconect it may not be fully unlocking.

 

I have an 01 f150 and I am having the exact same problem. I have changed out the 4x4 vacuum solenoids and the electric shift motor trying to fix it and it is still doing the same thing. Man this is really aggravating.

 

gsapatka- If you figure out what it was making that sound or how you fixed it, please post it on here.

 

They replaced the faulty 4 X 4 vacuum control solenoid. Here is what was on the invoice:

Verified concern WDS; No codes. Pinpont test SSM and TSBS; Removed and replaced part of front Trans Diff shaft collar for 4 wheel drive, checks ok. Trace vacuum coming on while not being commanded. Pinpoint faulty vacuum control solenoid. Replaced solenoid. Removed and replaced both outer hubs, pulled apart vacuum hubs at wheels. Removed and replaced halfshaft. Removed and replaced rotors and calipers. Road tested, checks ok.

It looks like they replaced hubs assemblies a vacuum switch nd R & R 'd the calipers and rotors for any damage.

Hope this fixes it...