[RockJeep]

We just bought a 2001 f250 and it has the shift on the fly. I was debating w/a friend on how it works. He says you don't have to lock the hubs for the 4wheel drive to work. i.e. auto . Now is there some sort of electric, vacuum, or hydraulic line that actuates the hubs that I don't see? if there isn't then wouldn't you have to lock the hubs like your regular front axle? Sorry for the newbie type question but I am to super dutys.
Thanks
bob

 

[Hillbilly]

I think its a vaccum line that makes em work. Somebody else will set me straight later. <IMG SRC="smilies/usa.gif" border="0">

 

[smurfsdad]

if it has manual locking hubs they will need to be locked first. shift on the fly just means that you can shift from 2 to 4wd at speed which you could always do anyway if you knew what to do

 

[Zukster]

You can use them as auto hubs (hence the "auto" writting on the hub) or manual hubs in the event of some type of system failure. When I had my Superduty, I always used the "lock" setting just so I knew it was engaged.

 

[Zukster]

Originally posted by smurfsdad:
<STRONG>if it has manual locking hubs they will need to be locked first. shift on the fly just means that you can shift from 2 to 4wd at speed which you could always do anyway if you knew what to do</STRONG>

The Superduty uses a somewhat unigue design, the hubs have both an "auto" setting and a "lock" setting.

 

[smurfsdad]

i learn something every day thank you

 

[F-350 PSD]

The hubs engage via a vacuum when the hubs are in "auto" if you turn the 4x4 on in the truck. If the vacuum fails, move the hub to "lock", this will lock them in 100% of the time. Hope this helps!

 

[DSI]

now when they are in auto both hubs are 100% disengaged correct? or does the driver side stay locked no matter what, and the pass side locks/unlocks? i just got mine last night and noticed a vac line to teh pass side, but not teh drivers?

it's 245 for teh kit from warn to conver to "normal" locking hubs

 

[F-350 PSD]

Both unlock when in 4x2 in the "auto" position (you are correct DSI).