4X4 not working right

[03F250PwrStrk]

When i have the front hubs on auto and turn it to 4x4 high in the truck sometimes it will stay on and then sometimes it just turns off... and if they are locked it works fine all the time any ideas why that would happen?

[mountainlander]

Originally Posted by 03F250PwrStrk

When i have the front hubs on auto and turn it to 4x4 high in the truck sometimes it will stay on and then sometimes it just turns off... and if they are locked it works fine all the time any ideas why that would happen?

Probably a leak in the vacuum system used to lock out the 'auto' hubs.

[03F250PwrStrk]

i wonder if that covered under warranty

[powerplant]

The vac lines going to the hubs come lose or dry rot and develope holes might check there first.