Hi all-

In the past all my vehicles have always had push button automatic 4wd, now I have a 2006 F-350 with shift on the fly and manual locking hubs. I read in the manual that it isn't good to drive on pavement with 4wd engaged because the wheels don't slip independently as easily, and could damage the vehicle. So what I wanted to know is, would it be okay to leave the wheels locked and only engage/disengage the transfer case when needed, or do I have to unlock the hubs every time I take the truck out of 4wd? The reason I ask is, recently we had a good snow storm come thru, so there are patches of snow where I need 4wd to get thru, but once I get thru the patches of snow the streets are clear and I don't need the 4wd. I am afraid that if I drive on the cleared roads too much with the 4wd engaged that it will damage something. What are your thoughts? Thanks again.

 

What you have as far as hubs with ESOF, are 'Auto lock' that are vacuum controlledthrough the selector switch in conjuction with the 4x4 transfer caseengagement/range.. The hub manual 'Lock' position is more of a fail safe control should the vacuum systemhave a problem or not lock..There isn't a real need to manually control the hub functions..

 

What is ESOF? Are you saying that even though I have to shift the truck into 4wd with a lever, Not a button, that I still don't have to lock the hubs? I thought that having manual shift and hubs was to get away from the automatic stuff? Sorry, but I am a little confused.

 

You said you have 'shift on the fly'..

ESOF stands for "Electronic Shift On the Fly"..

If you have a manual shift or a 'mechanical shift' transfer case, then its not ESOF or shift on the fly......

If you were to run in 'broken' traction conditions, mud/snow/wet pavement even occasional dry spots,,leaving the 'hubs only' locked isn't going to damage the running gear,, but full 4x4 engagement is bad on dry or hard packed surfaces.. So is 'overspeed' use if the hubs only are locked.. Better all around to unlock just for the added wear, MPG ect. but also,, the ESOF trucks sometimes won't unlock their hubs for miles until certain driving conditions, or backing ect are met...

 

Sorry for the confusion, I thought that shift on the fly meant manual lever (doh). Thanks again. So if I leave the hubs locked, for just a few runs around town, nothing over 35-40 mph, and shift into 4wd as needed, that should be okay? Of course this is only going to happen periodically.

 

No problem...

Guess that depends on the size of your town !

Shouldn't be a problem though,, even Ford's official position for the ESOF'auto lock' hubs systems forrelease once locked in, is thatthe 'actual times' required for the hublocks to disengage by spring force can vary considerably due to the effects of driveline wind-up. Road bumps, vehicle speed, acceleration cycles or momentary reversal of direction.. I can speak from personal experience that is probably more 'miles' than what you'd drive around town.. Sometimes not..

We have a pretty sizeable service fleet that run in pretty severe off and on road, and a combination of.... Most times unless being run out on the open highway, the drivers rarely unlock the hubs..

Unlocking them will reducewear, but nothing that would keep me awake...

 

Thanks!