Hi,

I have a 2000, f250 4x4, with the selector switch on the dash. Recently, the truck disengages on it's own. Also, it will try and re-engage and I will hear a grinding noise and then it will bang into 4x4 when it engages. Does any one have any ideas what the problem is? Thanks Tony

 

Sounds like a vacuum line has come off one of the hubs. Another possibility is the electric motor that shifts the transfer case. If you manually lock the hubs will it stay in 4 wheel drive?

 

Yes, If I Lock The Hubs Manually It Stays In 4x4. The Electric Motor Does Engage But It Pops Out Of 4x4 And After A While, It Will Try And Engage That's When The Grinding And Banging Into 4x4 Occurs. Where Would I Find The Vaccume Line. I've Greased The Front End And Never Noticed A Vaccum Line. Thanks Tony

 

The vacuum line is at the top of the axle housing, right by the rotor. It is a very small rubber line and could be off or broken. The transfer case will only engage when the hubs lock, thats why it stays in 4X4 when you manually lock the hubs. If you look over top of the tire you will see the line.

 

Thanks, I will check and let you know. I appreciate your help.
Tony

 

I did check the rubber lines to the front hubs they were fine, we then got a vacuum guage and tested the front seals that keep the truck engaged and we had one side maintain the pressure for 20 minutes and the other side dropped within one minute so the front seal is bad. I appreciate all of your assistance.

Tony

 

Glad you found the problem and that I could help. Tim

 

Good day, I did a quick search on the forum and low and behold you had to same problem I do on my wife's '03 F-350. I also checked the vacuum lines from the hubs and they look alright. Where is the front seal located that you said was bad on one side? Appreciate the help.

 

You cannot tell if there is a vacuum leak by "just looking". It takes a vacuum guage. The seal is in the hub.

 

I have the opposite problem on my F350. I will go over a bump in the road in electric 2w high and the grinding begins and stops if I immediately switch to 4whigh then back to 2wd.
What is causing this to happen?