Dusterdude72

In 2 wheel your front CV's should NOT spin. You can jack the front end up and spin a tire and if your cv spins with the wheel then your front hubs are staying engaged.

you can test the hubs themselves by popping the vacuum lines off of the IWE (Integrated wheel end) and hooking a vacuum gauge/pump to The large port on the IWE and pump it up to 7-11in lbs ( I believe) ....vacuum should hold and not leak down. And with the vacuum applied you SHOULD now be able to spin your wheel and the CV shaft should stay stationary. IF it still spins Then your IWE is likely bad.

you can also start the truck,turn the wheel so you have access to the back side, then while it is running and IN 2 WHEEL DRIVE, you should be able to pull the vacuum line off and put your finger over it and feel vacuum suction. You should then be able to switch it to 4 wheel drive and then feel the vacuum hose again and you should now feel NO suction!. This will help you narrow down if the IWE solenoid on the firewall is functioning. If you get little to no vacuum from the line with the engine running then the solenoid could have failed stuck in the 4 wheel drive position. OR you could have a vacuum leak in one of the lines or in the vacuum canister.

you can test the lines/canister by removing the line from the solenoid and hooking the vacuum gauge/pump up to it . If it doesn't leak down then the system should be good and the issue is likely the IWE solenoid (if you have already ruled out the IWE(s) as not being an issue.

Kind of complicated sounding at first but once you get a grasp of how the system operates it is actually fairly simple.

The IWE is mounted to the back side of the wheel bearing hub and also has rotating components. so it could very well be the cause of your noise. BUT I would guess that a vacuum issue originally caused whatever the issue with the noise is being that it sounds like your 4x4 is staying engaged.

Also you may find that if it is an IWE issue that the problem will be on the opposite side of where your hearing the noise. If your IWE on the drivers side fails ...the differential may try to engage power to the passenger side and cause damage .

Sorry for the long post. Just trying to help you narrow things down and give you a few ideas to test to maybe find you issue. good luck and let us know what you find!.

benc25

Thanks for the info, i will look into that. Would it matter if the truck is running? The only times I have spun the wheels it was not. I'm guessing it will not have a vacuum while its not running.

Dusterdude72

The vacuum system has a vacuum canister behind the battery and the system has I believe 2 one way check valves in it. Which stop vacuum from back feeding after the engine has been shut off. (These also help in regulating vacuum under acceleration as your engine produces less vacuum under heavier acceleration. (For example in 2 wheel drive hauling a trailer up a steep hill these prevent your IWE's from randomly trying to engage. It SHOULD hold vacuum at the hubs even with the engine off. If there is a leak in the system somewhere though then the vacuum will quickly bleed off and cause the IWE's to engage.

The things I mentioned previously I would check and that will give you a better idea as to if any of it has any issues. And can all be checked easily.

Let us know what you find.

The solenoid is a common issue (ford released a TSB on the issue. Mostly 04-05 f150's I believe.... After 06 they installed a rain hood on the IWE solenoid that prevents moisture from entering the solenoid). A new one can be got at your local parts store for about $18.00. And the IWE's at the local parts store for about $123.00 a piece....however I seen them on amazon from the same company for $112.00 for the pair. (Just to give you an idea on price Incase you find one of them to be the culprit).

benc25

Thanks I'll check it out this week

benc25

Finally figured it out! Ended up being the left wheel bearing.