i have a 2001 f250 4x4. when i put it in 4 wheel drive the auto hubs dont work so i have to manualy lock them in what could that be.

 

either something's wrong with your air lock system, the vacuum lines that go to your steering knuckles. or you can just go the old fashioned way and just get manual lockers, auto locking on these suck and they're not worth fixing, trust me

 

IMO get a set of Warn manual lockers... If you know you are going to use 4x4 that day then lock them in. Nothing wrong with leaven them locked if you are going to use it a few times a day.

 

Start from the top and go down the list. Pump working? then solenoid ( hit the 4x4 switch and stick your tongue on the hub lines. No vacuum? switch is bad). Hoses ? No cracks? Still connected to the hubs? Hub fitting not plugged up? If none of those it would be the hub seals. Just ordered all mine. Cost $120 with new needle bearings and studs.

 

superwinch makes a good set too for cheap

 

If you decide to get a set of manual locking hubs, that's fine but you still need to determine what the problem is with the vacuum system.

If the problem is somewhere in the vacuum lines, PVH valve, vacuum pump or hub vacuum lines, you can simply eliminate the problem by capping off the vacuum lines at the PVH solenoid and at the wheel hubs.

If the problem is due to a worn or damaged vacuum hub seal, your problems may have only begun. Ignoring a bad seal on the main bearing hub will allow moisture and dirt to enter the hub and begin to destroy the needle bearing and eventually the main hub bearings. It will not take long after the needle bearing begins to rust to take out your stub axle.

If you start adding up the cost of a new main hub, hub bolts, stub axle, labor to press the new u-joint on, new diff housing dust seal from pulling the axle, new vacuum hub seal and dust seal and labor to install the vacuum seal; a hand vacuum pump to diagnose the problem begins to look pretty inexpensive.

I have always tried to live by the rule that you should repair things when you first notice a problem. If you wait until it breaks, it's going to cost you 5 times more.

 

I agree with guzzle about finding the problem first then go from there. I personally DO NOT like any auto locking hub. They are for the soccer moms wanting 4X4. Get a set of the Warn hubs and install kit if you need it. For around $250.00 you will have hubs that you know are locked in. My dad always said you know when you will need 4X4, so just lock the hubs before you leave the house if it has snowed or lock them as you start down that muddy field, etc. Just my 2 pennies worth.

 

My autos are still working beautifully.... after 10yrs.......I did replace the vacuum lines to the hubs a few years back.....and I hit the hubs with WD40 around the circumference where they turn to keep them free from time to time......overall no complaints

 

I don't mind auto's. I do wish warn would make a better than stock version...

 

They are great as for the convenience BUT when you have to back down a 35% slope on a fire trail in the middle of PA with snow on it you suck alittle seat. After that I told myself I would never have auto hubs again!!!