2010 Locking Hubs Stuck

[biggy238]

Let me start this by saying I've done zero research.

I put my truck in 4X4, set the hubs to manual.
I put the hubs back in auto mode, and neither one unlocked. I've run it a long distance (1k miles?) at up to 80 mph at times, so it super pissed now.

First thing is, how do I get the hubs to release, and second is, what is the first thing to be damaged from prolonged axle engagement?

I assume taking the caps off isn't going to be enough to make them release, but I figured I would ask.

Kyle

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[PPUMPFUMMINS]

When u select 2wd and hubs are in auto mode there is a low vacuum pulse sent to hubs to unlock them. Are the hubs hard to turn by hand?

[biggy238]

No, they aren't hard to turn/select.

I went back out to it, and unhooked the vacuum line, set the driver hub to manual and back to auto, and it unlocked (wheel off the ground).
I raised the passenger side and it did the same thing. It was engaged, I turned to manual and then auto and it unlocked.

I'm guessing this is a problem with the solenoid?
When I bought the truck, it wouldn't engage the hubs in auto. That's why I had set them to manual during the weather a week or two ago.

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[PPUMPFUMMINS]

Most common issue is the pvh solenoid. (Pulse vacuum hub). You can test this by installing a vacuum gauge,or use the gauge on a vacuum pump, into one of the vacuum lines and move the 4x4 switch between 4x4 hi and 2wd.

[PPUMPFUMMINS]

You'd should have source vacuum in 4x4 hi and if I remember correctly you should have about 7in/hg during disengagement

[biggy238]

Thank you for this. Those specs are exactly what I wanted to hear. I will check it out tomorrow.

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[PPUMPFUMMINS]

Hublock Operation

With the hublocks in the AUTO position, the 4WD ESOF system uses timed vacuum sequences to lock and unlock the wheel ends when switching the instrument panel MSS between 2WD and 4WD modes. A high vacuum level (222 mm [8.75 in] Hg and greater) is applied to the hublocks to lock the internal spring mechanism that engages (locks) the hublocks for 4WD mode, and a lower vacuum level (114 to 184 mm [5.9 to 7.1 in] Hg) is applied to unlock the spring mechanism that disengages (unlocks) the hublocks for 2WD mode. The vacuum signals are supplied to the hublocks by system components, including the 4X4 control module, wiring harness, solenoid, vacuum harness and vacuum seals. As a first step in service, eliminate obvious items such as loose wiring connections, loose vacuum connections or damaged vacuum lines.

Hublock Engagement/Disengagement Time

With the hublock dials in the AUTO position, switching the instrument panel MSS to 4X4 High or 4X4 Low results in the high vacuum level being applied to the hublocks, which lasts for at least 51 seconds (including a venting cycle). The hublocks should engage during this time through the spring mechanism. Switching the MSS to 2WD less than 51 seconds after the MSS has been switched to 4X4 High or 4X4 Low will not interrupt the high vacuum level; instead, the lower vacuum level will be applied after the high vacuum level cycle is completed.

With the hublock dials in the AUTO position, switching the MSS to 2WD results in the lower vacuum level being applied to the hublocks, which lasts for about 15 seconds. However, the actual time required for the hublocks to disengage by spring force can vary considerably due to the effects of driveline wind up. Road bumps, vehicle speed, acceleration cycles or momentary reversal of direction can assist this process. Switching the MSS to 4X4 High or 4X4 Low always overrides the lower vacuum level cycle and results in an immediate high-vacuum level and in locking of the hublocks.

Manual Override

The AUTO hublocks have a manual override selector dial, which, when turned to the LOCK position, will keep the hublocks locked (through the dial) at all times, regardless of the position of the instrument panel MSS . (Always set both hublock dials to the same position.) If the hublock dials are manually turned from the AUTO to the LOCK position, and the high vacuum level is applied to the hublocks (by switching the MSS from 2WD to 4X4 High or 4X4 Low), the hublocks will be locked through the dial as well as through the internal spring mechanism. In this case, turning the hublock dials back to the AUTO position will leave the hublocks in (spring) locked mode until the lower vacuum level is applied to the hublocks (by switching the MSS from 4X4 High or 4X4 Low to the 2WD ). (This is not an issue if the hublock dials have been in the AUTO position and the MSS has been switched from 4X4 High or 4X4 Low to 2WD at least once.) Alternatively, the hublock mechanism can be reset to free mode at any time by turning the hublock dial from AUTO to LOCK to AUTO at least 2 times.

[PPUMPFUMMINS]

if you find the solenoid to be bad, base part number is 9h465

[biggy238]

The last few statements detail what I experienced exactly.

Are owner maintenance manuals still available for customers?


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