I have a 2004 F350. I always had free and lock on the hubs and now this truck has lock and auto. If I turn my electronic switch to 4wd with the hubs in auto, what does this do? When I go to lock I assume they operate normally as a 4wd? Thanks

 

You can be in 4wd with the hubs in the auto position. What the auto does is keeps you from having to get out of the truck and manually lock the hubs. A vacuum pump does this for you. Hope this helps

 

You have what is called ESOF (Electronic Shift on the Fly).. It has a few advantages, and disadvantages..

Your hubs have two locations, Auto and Lock. Auto allows you to flip the selector switch to 4HI or 4LOW at anytime you choose. That can be moving down the road or sitting still. Lock allows you to MANUALLY lock the hubs as a fail safe. A reason for this is something such as a vacuum leak or a bad line that would cause your hubs to unlock under Automatic operation. Generally when this occurs your AC/Heater will default to "Defrost" (air will be sent out the window vents instead of the front dash vents), which indicates you have an air leak somewhere or possible bad solenoid.

ESOF has its quirks. If you take care of the 4WD system, you should be problem free.. There are times when folks have needed it and sure enough it's dead.

One major advantage is the ability to run "Unlocked" and switch to 4WD when you need it. Unlike myself, I have Manual Transfer Case and Hubs, in order for me to have 4WD when conditions warrant it but not require it immediately, I am forced to lock my front hubs with my TC still in 2WD. This reduces my MPG and increases wear.

For the moderate Offroader, I'll stand by Man TC/Man Hubs.. But for those folks in the Snow/Ice environments, I see now why ESOF is a good thing to have


Little insight.. As for your question, hubs in "Auto", flip switch to 4HI or 4LOW, you will engaged the Transfer Case and your truck will be in 4WD. Now you can switch in and out at speeds below 50mph (per owner manual), however some of actually drag race in 4WD. It's a pretty stout system so if your going 60mph and you hit ICE, flip the switch. Your not going to hurt it, might jerk the living crap out of you but it's going to get you the traction you need immediately.

 

To get into 4WL actually requires you to stop and be in Neutral. Other than that Storm is dead on. My experience is that ESOF can be great but can fail to be there for you sometimes. I reccomend engaging it every so often to make sure it works and to spin some fluid around a little.

Were you busy today Storm - we had some great chaser weather down here near Houston.

 

Not really.. Nothing but a small constant down pour.. My HAM license expired and I've been a lil lazy to get it reinstated =\ Without that I'm somewhat blind when I'm out..

I've been doing it since 99' and I dunno, just lil wore out lol..

 

Do not get stuck then expect ESOF to work. You will need some forward movement to lock the hubs.

 

I think the manual states a (1 mph?) speed is required for esof to engage, movement is required, but it will engage if the wheels are spinning while stuck as its looking at wheel movement not vehicle movement. I love it when in the snow & ice. Had a bit of a learning curve at first as I was expecting to have to be in neutral & stopped for it to engage, it wouldn't happen until there was a little movement. 4 lo does require neutral and stopped though. After getting out the manual in a snowstorm and reading a bit I found out just how convenient it is, also like the fact I can leave the hub caps on.

 

4x4low will require stopping in nuetral with the foot on the brake.

 

Thanks...yeah in my last trucks...for 4 high you can engage up to 55mph and is best to be moving a little bit to get it to engage...for 4 low its best fo coast at 1-3 mph...shift to neutral while rolling and then shift to 4 low...or stop...shift to neutral then 4 low then go forward slowly...now I do have a question...The "lope" you get while turning sharp in 4WD I get when I engage it manually but today I tried it while in auto and I didn't get that lope...maybe I didn't wait long enough (only a few seconds) or maybe I have a vacuum leak...I will crawl under there and check..If it engages I should not be able to spin the front drive shaft freely by hand while stopped correct? Thanks

 

you can renew on line now it makes it really easy

 

my 06' still has the 4X4 shifter on the floor and locking hubs...had to order it that way....hope they offer it that way forever....It works way better.