Ok I some understanding of how the 2h,4h.4l works as far as the system using vaccuum to work the problem im having is that when i cut the engine off i hear a thump from the vac solenoid on the fire wall and then the passengerside shaft locks the wheel in and the wheel will not spin freely , but will spin freely while the engine is running and the dash selector is in 2h in both instance does any body have an idea what to correct this.

 

Why is it in this forum when a question is asked you can have dozens even hundreds of veiws on a subject and there will be zero replies, knowing dang well that the question or problem a member has or is looking for an answer has never been across the forum(and yes I do know how to use the search so don't go there) , but instead of trying to scroll through pages somebody could offer an answer or idea) I can't beleive the member asking the question is only one that has had the same problem .

 

There's nothing wrong with your 4x4. After you shut the engine off, your vaccuum (which is used to keep your hubs UNLOCKED) is no longer being produced, and will go away, and the hubs will lock. Your hubs are always locked when you shut the engine, no matter whether in 4wd or 2wd. They unlock when you start the truck and produce vaccuum again, unless its in 4x4. The Fords use a "negative vaccuum system". Other makes use vaccuum to LOCK the axles.


Bottom line. truck off in 2 or 4wd = hubs locked
truck running 2wd = hubs unlocked
truck running in 4wd=hubs locked

 

There's some more understanding ...

 

Thank you driver444 thats all I was needing was some more clarification.