4WD trouble

[03 CLASSIC]

HAVE A 2003 WHICH I THINK IS PARTIALLY STUCK IN 4wd. FRT DRIVE SHAFTS TURNING WHILE IM IN 2WD.iT GOES IN AND OUT OF 4WD ok ,but dont think front end should be turning in 2WD. Anybody had same problem?

 

[KWT2000]

i thought 99 and newer were all time four wheel drive,

 

[cdherman]

2003 - 2006 have vacuum lockout hubs on front. The way they work is that vacuum pulls a ring gear over, and then the CV joints are no longer coupled to the hubs.

When they lose vacuum, they engage. If they partially lose vacuum, they can partually engage and rattle, catch and destroy themselves. If you hear them grinding and halfway engageing when the vehicle is in 2wd, the short term solution is to put it in AWD setting, which dumps the vacuum and usually fully engages them, which prevents further damamge. But from that point on, the front differential and the CV joints are running all the time, which at least theoretically will wear things out more quickly.

If they are BOTH engaged up front, then I thinks its unlikely that the actuators themselves are the problem. Instead, it may be that your vacuum solenoid, which is what regulates the vacuum to the front hubs, is not working. The switch on the dash does not directly regulate the vacuum -- -its an electrical swith that runs a vacuum solenoid somewhere (I have read about it, but personally never had to fix).

Anyhow, perhaps knowing how its supposed to work will help you figure out where your problem is.....

 

[03 CLASSIC]

thanks for the info.i put the truck on stands and the wheels turn in 4WH and 4WL, when i put it in 2WD the wheels don't turn but the frt shafts are all still turning.i only feel a slight vibration,no noise.so if the transfercase is shifting right can the hubs still be turning the drive shafts if the wheels are not turning?replaced vacuum soleniod still the same.

 

[p-351]

I've got an 04 that was doing the same thing, the CV shafts were locked in all the time. I had some vibration coming from the front going down the interstate and the gear lube was kind of metallic looking when I changed it out.

My solution (for now) was to take the vacuum line off of the solenoid on the passenger side firewall and jumper the line with a piece of hose I had laying around. It unlocked the shafts, but as you probably can figure out---4wd will not work right now. With winter fast approaching up here in North Dakota I suppose I'm going to have to track down the real problem.... When I get it figured out I'll post my fix.

 

[KC Dave]

Did you figure out the problem?

 

[alaskanexpy]

i thought 99 and newer were all time four wheel drive,

in '03 they added the 2HI option back like the 97-98s had.

 

[mindgame]

2003 - 2006 have vacuum lockout hubs on front. The way they work is that vacuum pulls a ring gear over, and then the CV joints are no longer coupled to the hubs. ...

Thanks!!!! I will explore this... I think I am also experiencing this same issue now...

 

[fireman643]

Me too

I Think this is the same Issue I am Having, So any help from any one? What is this? IWE solenoid? where is it and how can i fix/ replace it. I have already changed the transfercase moter ( no joy ) so If i find a fix first I will post it here too.

 

[ericnyce]

I'm having no luck pin pointing my front end hummin noise. I changed all the hub assemblies and front and rear diff fluid...I also realized that unless your truck is on, theres no vacuum so the front end is engaged like it would be in 4x4 so turn it on while its up so you can determine if the solenoid (behind battery on firewall) or actuators are gone. Lucky for me I didn't open up the actuator so thats going back to the dealer.

Heres a good site to look at, i found it today.

http://www.f150online.com/forums/2004-2008-f-150/360269-iwes-removal-replacing.html