auto 4x4 hubs not working/vacuum leaks
 

I have a 2005 6.0l with auto hubs not working I have replaced the vaccum switch I have voltage on the center pin but not ont the outer pins to the switch when switching from 4x4 to 4x2. I have checked fuses all are good. Its just not switching back and forth all the lights work and you can hear the transfer case switching. Any Ideas??????

Leaking vacuum hubs most likely, or one of the vacuum lines itself, quite common. Does your heater/A/C go to defrost when you turn the switch?

This should help you out, this video is going to be a sticky here soon...

Thanks Mdub707
 

I'm have the same problem. Followed your video. My Defrost came on just like you said. I didn't find any leaks. After about five minutes the defrost went off and I appeared that my Hubs locked and unlocked. I haven't use it in over a year. Do you think that is the reason it took so long to engage? Still troubleshooting. tks Joe:s:

Joe, very possible man. Just keep using it and see if the problems go away or if they persist... Let us know.

Thanks
 

I will keep trying them out. I went through and checked all the connections and my lines from the frame to the hubs looked great. (No cracking and very flexible):tu:

Not to be a smart a$$ but im still learning as well and i know that sometimes you have to go almost 30 feet in reverse for your hubs to lock. Im not familiar with auto hubs, but could this be the case?

These usually lock right up or not at all. The vacuum system leaking is very common. My auto selection hasn't worked for like 3 or 4 years, I really need to watch this vid myself and fix mine haha.

You can make sure the hubs aren't bad by getting out and turning them to "manual"... which is what I've been doing all along.

Hubs sometimes "gunk" up or the cut washer that the vacuum passes thru will plug up with grease but usually its a vacuum leak if they wont lock, crud if they wont unlock. Best a luck. I hate when they come into the shop for hub work :argh:

My truck recently had the EGR delete kit put in and I have now realized I have this problem with the defrost coming on. Don't know if there is any connection or not but the video above is very helpful and seems simple enough. My question now is I went to try and move the locks manually and only the passenger side turns slightly and I dont want to try any harder to turn them. I seen the video on maintaing the hubs and im guessing the previous owner of my truck hasn't. Does the somewhat seizing of my hubs mean they are junk?:s:

I had same issue on my `03. I just picked up some Warn manual locking hubs for $200 on sale from NAPA. Just throwing an idea out there.