auto locking hubs
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auto locking hubs
2000 f-250 auto hub not locking when in auto put seal kit in this weekend per guzzles site, still not working i have vac to hubs, left side will hold vac right side will not [with hand vac pump] whats next?
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Which seal kit did you use? There are several "seals" on the hub so that you can draw a vacuum to your hubs. There's a black o-ring on the locking hub, a yellow o-ring on the main wheel hub itself and a large axle seal on the inboard side of the steering knuckle. All of these work in concert to seal the hub so you can send the vacuum "pulse" to lock/unlock the hub.
In addition to the seals on the hub, you can have a vacuum leak in the line between wherever you connected to draw a vacuum on the hub and the knuckle (the rubber hose where it attached to the knuckle is a common failure point). You also may have a frozen hub. Unless regularly maintained (i.e. driving around in the dirt in 4wd at least once a month) the locking hub could freeze in the locked or unlocked position (happened to me).
It's hard to pinpoint a troubleshooting route without actually being there and seeing it, so I've thrown out some of the things that it could be. Except for the rubber hose from the wheel well (from the plastic tubing) to the knuckle, none of it is cheap either.
I'm not a mechanic, so this is just my .02.
In addition to the seals on the hub, you can have a vacuum leak in the line between wherever you connected to draw a vacuum on the hub and the knuckle (the rubber hose where it attached to the knuckle is a common failure point). You also may have a frozen hub. Unless regularly maintained (i.e. driving around in the dirt in 4wd at least once a month) the locking hub could freeze in the locked or unlocked position (happened to me).
It's hard to pinpoint a troubleshooting route without actually being there and seeing it, so I've thrown out some of the things that it could be. Except for the rubber hose from the wheel well (from the plastic tubing) to the knuckle, none of it is cheap either.
I'm not a mechanic, so this is just my .02.
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Brain 42 Thanks for the reply,the seal kit i used was the ford seal kit comes with big black oring and new snap ring, as for vacuum leak in line i hooked my hand vacuum pump to the nippel on back of knuckle,no frozen parts in side of auto locking hub went through cleaned and greased. could the rubber bladder be bad ?
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If your hubs are okay then the only things left are the rubber lines in the wheel wells, plastic tubing that runs through the engine compartment, this connect to another rubber line (on the passenger side near the wheel well) that connects to the solenoid. After that you have a plastic vacuum reservoir and the vacuum pump.
If you want to narrow it down, you can plug both rubber ends that go into the knuckle (or have a couple of friends put their finger over the opening), and draw a vacuum from the solenoid (disconnect the hose and plug into it) to see if your vacuum lines running to the hub are okay. After that, all that's left is the solenoid and pump. The vacuum pulse is not long and not very large, and you can test it. Hook your vacuum gage up to the rubber line coming out of the solenoid (that would have gone to the tubing going down into the engine compartment), and have a friend click your ESOF in 4wd (with the engine on of course) and see what you get. IIRC it's only around 15" vacuum for 20 seconds or so. To go back to 2wd the pulse is the same length and only goes to around 10" or so. I don't remember the exact values off the top of my head, but you get the idea.
If you want to narrow it down, you can plug both rubber ends that go into the knuckle (or have a couple of friends put their finger over the opening), and draw a vacuum from the solenoid (disconnect the hose and plug into it) to see if your vacuum lines running to the hub are okay. After that, all that's left is the solenoid and pump. The vacuum pulse is not long and not very large, and you can test it. Hook your vacuum gage up to the rubber line coming out of the solenoid (that would have gone to the tubing going down into the engine compartment), and have a friend click your ESOF in 4wd (with the engine on of course) and see what you get. IIRC it's only around 15" vacuum for 20 seconds or so. To go back to 2wd the pulse is the same length and only goes to around 10" or so. I don't remember the exact values off the top of my head, but you get the idea.
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Joined: Dec 2006
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From: San Diego, CA
Plastic hose (engine compartment) connects to rubber hose (wheel well) connects to knuckle (common hose failure point). Inside knuckle there is an inner seal that seals the axle shaft and the knuckle on the inner (ball joint side) side of the knuckle. There is an o-ring that goes on the hub (the infamous "yellow" o-ring) that seals the hub to the knuckle. There is also another black o-ring that seals the auto-locking hub to the main hub assembly. That's the path of vacuum from the engine bay to the hub to pulse it.
Another thing to consider is a frozen hub (I have personal experience with this). If you have the auto-locking hub piece out, see if the inner portion spins freely. Now move the **** to lock and try to spin the inner portion again. It should almost immediately lock on you and not move. If it doesn't, guzzle has a great write-up on how to service this (OEM replacement is $200-$300...no aftermarket ESOF hubs available): http://www.guzzle7pt3.com/allube.php
This is just to give you an idea of the vacuum path to help in any diagnosis...
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