I have read most of the thread for the "Everything you want to know"

I tend to do better if I can ask my own questions.

Here's my scenario.


2006 F150 Lariat, 5.4

Went on the beach one day, 4x4 went out after being parked for about 4 hours. Wasnt playing around, just drove out and parked.
Got towed out, and started messing with it.
Pulled the vac lines off, didnt notice any water, no tears in the cv boots.

Drove it for a few days, and it would stutter while driving. Like it was going in and out of 4x4. If i turned the switch to 4x4 on the dash, it would stop.
So, I left it on for a few days.

It seemed to be working fine, and the dealership said it probably had sand in it. (to which I argued with him)
Nonetheless, I tried it in a gravel parking lot, and got the grinding/ ratcheting noise.

So, I just went out and did some of the checks based on what I found on youtube ( )

If i lift the vehicle off the ground, and leave the engine on...
Pull the passenger vac line from the IWE, the CV spins. If i add 25-30 vac, it still spins, and I lose about 2-4 vac per minute.

Here's the kicker... If i do the same thing on the drivers side, it holds vac, but I cant get the shaft to spin at all.

I am 90% sure that the driver is the one that made the noise as well.

If I pull either vac line off at the IWE, they both have vac on them when in 2wd, and no vac in 4wd.


Im here, and ready to do any tests I am capable of to help figure this out.

TALK TO ME!

 

When in 2wd, the IWE gets vacuum that unlocks it. So if you are putting vacuum to the passenger line and the CV joint is still spinning, then it is bad. Vacuum means unlocked. No vacuum and the CV should spin.

 

It seems as if neither wheel is acting correctly.

One wheel, the shaft turns with and without vac, the other doesnt spin with or without vac.

Im guessing I need to replace both.

 

Sounds like it. Shaft should not spin with vacuum, and should with no vacuum.

 

Pull both hoses off the solenoid and connect them. See if you still have the grinding noise while driving. This will essentially lock in 2wd. This test will prove whether or not your air lines and hubs are good. If you the grinding quits then the solenoid needs replcing. If the grinding goes away you have a vacuum leak somewhere.

I just went through all of this with my 05.