New to the forums here. Having probs with my 4 wheel drive. 2005 F-150 4x4, 6 in. lift. I have auto locking hubs, when I engage the 4x4 you can here the transfer case engage and the axles are also locking but my hubs are not locking.

Anyone know what the issue might be, or even a link to a previous post would be helpful. I have searched the forums and found multiple problems with the 4x4 engaging when you dont want it to, but none on this problem.

Thanx all

 

Might have a busted hub seal. Same thing happened to me. Easy fix. About $100 bucks for part and install at a local mechanic.

 

Found a post on checking the vaccum to the IWE's. Pass side has vaccum drivers side does not. Started tracking the lines back and found that one of them is broken but i cant find the rest of the hose. Dont know where it is suppose to connect to.

Is there a vaccum diagram for the 4x4 anywhere?

 

I just changed the vacuum line set on my 06 cause I had a leak on the passenger side. The lines run from the top of the passenger strut tower down the front and under the radiator support where there is a splice in the line where you can seperate it and just runs back upover the drivers side tower and down to the IWE. There are two lines coming up from each wheel end. One is the vacuum and one is a vent that just runs up and then has a bend back down on it so water doesnt go in it. They should be easy to trace. Im surprised that one side has vacuum and the other doesnt. I know there are check valves in the lines, but I didnt think there was one in between the sides. you should pull off the drivers side hose off the IWE and cap the larger opening, and then disconect the lines going into the selenoid and use a vacuum pump to make sure its the line, and not a rip in the boot inside the IWE itself.

 

You can go to Tasca parts and put in part number 7L3Z7A785A. That is the line set and there is a diagram for it too.

 

Thank you. That was a great help. I didnt realize the vent line was just a dead line and didnt connect to anything. Thats what i thought was broken. I will do a vaccum check as soon as i can. Maybe its just a bad check valve or something.

Glad i signed up here you all were a great help.

 

Your welcome. The way the system works, is that if you loose vacuum the hub will lock. If you disconnect the lines going to the selenoid and cap the one that actually conects to the manifold for vacuum, both your hubs should lock and the axles will spin. If you do that and the one side still isnt engaging, you may have a problem with the wheel end itself.

 

https://www.f150forum.com/f72/how-di...m-esof-186872/