Hgkoch

Howdy everyone-
On my 2007 f-150 I have been experiencing a recent problem. When I switch it to 4 wheel drive, the hubs will not engage. When I drive with it in 4x4 there is a loud metal on metal clicking/rubbing/ticking sound. As soon as I put it back in 2 wheel drive the noise goes away. I have already tested the vacuum lines and solenoid that engage the hubs as well as replaced the lines once before. In 4x4 the noise does not seem to be there when in reverse, and seems loudest when driving forward with the wheels angles. Any ideas on what this could be would great.

Thanks,
-Hunter

whomrig

are you driving in 4x4 on asphalt? you should not do that

Hgkoch

I did some today just to see if the hubs would engage. There used to be a leak in the vacuum line that would make the rattling noise when driving in 2 wheel drive, and the hubs would not engage if I remember correctly. After replacing the vacuum lines 2 wheel drive would work fine, but the hubs have never been able to engage since. Have gotten stuck a few times where it woulda been a help.

Hgkoch

But no, I don't drive in 4x4, I was just saying "driving in 4x4" meaning when I have needed to use it.

whomrig

ok, had to ask.
keep checking

Dirttracker18

You need a vacuum pump/gauge to test the hubs themselves. They should take and hold vacuum, if not they need to be replaced. Check both, should be no leak down at all.

Also check both outer CV joints, could be source of the noise and the front driveshaft. I had the rear u-joint on the front shaft good bad and it made an terrible noise and was a real bear to change.

Hgkoch

Thank y'all, appreciate it. I'll check it out and see what I can find

tomb1269

Our hubs disengage when vacuum is applied and engage when vacuum is released. If you have not replaced the IWEs then it is most likely time to do so. The vacuum release solenoid is at the firewall just behind the battery. If it does not have a shield over it, then make one or buy a new switch as without a hood it will suck in water coming of the windshield cowl when you engage 4 wheel drive in any wet conditions, i.e. rain, snow melting off the windshield, etc.


FYI if you do them yourself, it is also a goodtime to replace upper control arm (ball joint is not replaceable - MOOG $65ea from Rockauto) and your lower ball joints (moog - $20ish ea from Rockauto) as it is easies to replace by pulling the spindle off to replace IWEs and might as well do the ball joints while you're at it.

EBC-150

More than likely your IWE's are worn from all the previous 2WD 'rattling' you were experiencing. That was actually the IWE's partially engaging and grinding. Since you took care of that problem, you'll now need to replace those worn IWE's.

Dirttracker18

The issue with the solenoid is not sucking in water, if that were to happen it would only end up in the engine, not migrate back down (against the vacuum) to the IWE. This would also mean there was a vacuum leak and cause other issue with how the engine runs. There is always vacuum at the solenoid, it acts as a switch to stop or allow vacuum down to the IWEs.

The issue is water getting into the electronics and stoping the solenoid from functioning.

Why would you replace any front end parts if they are not worn out? Seems a huge waste of time and money.