Long story short, I have a small vacuum leak in the 4wd system. I disconnected the lines going to the hubs to prevent grinding them to pieces as they are brand new. This, of course lock the front hubs in and disengages the X-fer case in 2wd.

It is not engaging in 4wd unless I select it, so I don't imagine it hurting anything in the X-fer case or anything. Other than the extra rolling mass, is this okay to operate at until I resolve my vacuum issue, provided I close all openings and places for trash to get in?

 

First and last bump

 

It's not going to hurt it for a little while...maybe a few hundred miles, but dont drive it like that for months. vacuum leak......common areas are inside the front wheel knuckles. They get water in them and rust where the IWE and behind the hub and bearing where the o'ring seals against the knuckle. The surface of the steering knuckle becomes too course to seal. Out a vacuum pum on each iwe while its installed and see if they hold vacuumm.

 

I assume I've got the same thing going on, starting to grind intermittently in the front end. Is it normally vacuum problems or maybe a solenoid?

 

Both solenoid and vacuum are common problems. The solenoid controls the vacuum and is on the pass. side fire wall.

 

Basically, if you can switch into 4wd and the grinding stops, it's not too late. Best advice would be to do what I did and disconnect the vacuum lines from the solenoid. This will cut vacuum to the system and lock in the hubs. 4wd will not be enabled unless you select it. Then start diagnostics on the system

If it feels like the hubs are letting go when you turn in 4wd, the teeth may have ground out too much and you will need to replace.

But yes, vacuum and solenoids are a HUGE common problem. On some year models, the drip cowling would direct water directly onto the top of the solenoid, shorting it out. The vacuum system is a series of small lines and check valves that may leak. Also the hubs themselves can malfunction over time and not be able to fully lock in.

This is by far the best write up on the IWE system.

 

Mine is really intermittent, it will happen and then you won't feel it again for maybe 3 or 4 days, maybe a week. Makes me wonder if it's mechanical ( vacuum ) or electrical (solenoid ).

 

You may have a slow leak somewhere in the system. It can leak from the solenoid and the actuator as well.

Get a vacuum pump and get to testing! It's not that bad really once you start looking at it. Worst case your hubs may be leaking and you need to replace them. Pull vacuum on them and see.

Is it grinding from one side or both?

 

Just the left side as of right now. Just started not too long ago.

 

Definitely check that hub first. Diaphragm might be leaking.

 

Your fine driving around with them locked in. I unknowingly drove around for months with mine locked in before i even knew what was going on, or that something wasnt right. Heck it could have been years for all i know. Mine never made the grinding noise, so they could have been shot and locked in when i bought it, and i never fixed the things for 2 years. After i fixed it everything else was fine.

 

Ok thanks guys
I just made a trip to Destin from Louisiana without any issues . I just didn't want to drive all the way there with them grinding down.

 

The new unit for Ford has a cover / hat on top of it to prevent cowl water from dripping on it. Had to replace mine, glad at least Ford's new part has a fix.

 

I'm dealing with that now on my 07 F150 FX4 with 165,000 miles on it. Changed the solenoid and its still doing it. Can hear it on both sides. Just started last Sunday. Need to start troubleshooting lines in the morning.