Just bought this 2003 4x4 w/o the owners manual and I am a little confused on the locking of the front hubs?? Am I correct to assume that if I want to go into 4 wheel high that I must manually lock the front hubs before I throw the switch to 4 wheel high?? But then if the front hubs remain in the manual unlocked position will the high vacuum going into the hubs lock into 4 wheel (using the interior apparutus and springs and diaphragm within the interior of the hubs) , and if this is the case would the hub lockout ***** remain in the unlocked position, or do they turn themselves from the vacuum being introduced into the hubs??

--as you can see I am a complete neophyte for 4 wheel drive--any comments would be greatly appreciated!! Larry

 

With ESOF, you don't have to turn the *****, assuming that your ESOF is working properly! When you turn the switch on the dash, the t-case engages and the hubs lock automatically. Similarly, when you turn the switch back to two wheel drive, they will unlock automatically.

The selectable locked position is basically a backup in case the ESOF fails.

All that being said, its a good idea to exercise the ***** occasionally. You'd be surprised how hard they can be to turn if its been a while. Which defeats the purpose of having them as a backup.

And, its a good idea to service the ESOF hubs occasionally to make sure they keep working properly. Here's a good write up on that:

Welcome to guzzle's 4x4 Autolock Hub Lubrication Maintenance Web Page