Locking Hubs

[middleroadsupply]

Have a 2001 F250 that has hubs which say "AUTO and Lock". Can anybody tell me how these work? When in auto it won't go into 4 wheel drive. Only when the hubs are in the Lock position.

 

[O'Rattlecan]

Auto is going to try and detect slippage in the rear axle. When it does detect the slippage, it will try to engage 4wd. I'm not a big fan of this option, but that's what it is designed to do.

Ryan

 

[middleroadsupply]

In the book they mention a pulse vacuum hub lock solinoid. Could ti be that this is not working

 

[rambler]

yes it is usually a vacuum leak going to the hub. One hub on mine is froze up and will not even turn now so stuck in "off" .. so will probably replace it with manual hubs..

 

[aussie_f350]

They are vacuum operated with switch on dash that operated transfer case too. They are not the best, often don't lock in and then won't come out at times too. I'm replacing mine with warn premiums, but mile marker are good too I have read.

 

[middleroadsupply]

There is a hose connected to the steering knuckle that must operate this, but I can't see how the bearing assembly can be that tight. If the seal gets worn then the vacuum won't work. Correct?
Anyway the 4 wheel drive works when we lock the hubs, so I guess we'll just pretend the hubs are manual hubs. We just replaced both hubs and those weren't cheap. Thanks for all your help.

 

[blacksnapon]

Diesel or gas motor? Diesel has an electric vacuum pump, gas uses engine vacuum.

 

[middleroadsupply]

It is a diesel

 

[blacksnapon]

If the vacuum pump isnt working, no lockouts. Does your heat only come out of defrost vents? If no vacuum, its designed to default to defrost only. The 4x4 solenoid is by the pass battery. You can check the integrity of the vacuum lines with a vacuum pump. Apply vacuum directly to the nipple on the knuckle and see if the hub locks.