Front hubs not auto locking
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Front hubs not auto locking
OK, I'm stuck. My hubs will not lock when put into 4x4. I disconnected all lines from the solenoid to both hubs and tested them for leaks... All good there.
I put a gauge on the lines at both hubs one at a time while the other is still connected and get no reading when switched into 4x4. I checked for vacuum right out of the solenoid, and I get 2inHg when switched into 4x.
The vacuum pump kicks on every time I start the truck, even if I just shut it off and re-start right away. There is no delay when switching my ac/heater controls to different settings or vent locations. So I know there is vacuum.
Any suggestions on what next? Or how much vacuum I should be getting out of the solenoid to the hubs?
'04 F350 6.0l
I put a gauge on the lines at both hubs one at a time while the other is still connected and get no reading when switched into 4x4. I checked for vacuum right out of the solenoid, and I get 2inHg when switched into 4x.
The vacuum pump kicks on every time I start the truck, even if I just shut it off and re-start right away. There is no delay when switching my ac/heater controls to different settings or vent locations. So I know there is vacuum.
Any suggestions on what next? Or how much vacuum I should be getting out of the solenoid to the hubs?
'04 F350 6.0l
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Joined: Nov 2004
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Have you tried manually locking the hubs?
if you manually lock them, and the 4wd still doesn't work, then something's wrong with the 4wd switch or transfer case. It's possible that the physical hubs may be bad, but I doubt they would both all of the sudden fail
if you manually lock them, and the 4wd still doesn't work, then something's wrong with the 4wd switch or transfer case. It's possible that the physical hubs may be bad, but I doubt they would both all of the sudden fail
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Yes, They lock manually just fine. Had to do that to get out of a field (how i found the problem) And when doing the trouble shooting I did, I locked both manually, lifted front wheels off the ground, and spun the wheels just to verify.
Tuned
Joined: Feb 2015
Posts: 323
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From: Tulare, CA
Not sure about a diesel but on my 6.8L I had the same problem. I removed the locking hubs & greased them with high temp red grease, O rings were good added a little grease on them too while I was at it. Checked with a Mighty Vac and they engaged But wouldn't engage using the in cab selector switch. The A/C, heat & defrost all worked as it should. I had vacuum at the PVH Valve & I couldn't figure what the problem was UNTIL my starter went out located on the passenger side of the truck. Then I saw it - the plastic vacuum line running down the frame near my exhaust manifold was melted in two. I guess the heat melted it and the vacuum sucked it together so there was no loss of vacuum. I bent up some 1/8" stainless tubing we had at work that now runs from the vacuum reservoir tank past the frame and my exhaust manifold. Everything works fine now.
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dogerbrown1
1999 - 2003 7.3L Power Stroke Diesel
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Sep 22, 2010 06:43 PM
