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I recently scanned my pcm on my 2005 f350 for some codes due to a tbc fault warning(I've solved this), but i also found some transfer case codes. I've found: P1876 and P1832. Could this be related to the fact that my auto locking hubs aren't working, or is it something else? It engages 4wd high and 4wd low just fine, no issues there, and when the hubs are manually locked the system works great. Lastly, a few weeks ago I was going through some mud on a sharp turn going around 8 mph, with 4wd high on and during the turn I felt a lot of almost binding feeling? I always thought this was normal when it's in 4wd on sharp turns but maybe this damaged something and is causing the codes?
Based on a quick internet search, it does appear those codes might be related to the control solenoid for the hubs. Might be bad solenoid, rotted or missing vacuum lines to the hub or the hubs themselves. Since 4x4 works with manual engagement of the lock-out hubs the shift solenoid should be okay.
If you turn sharp with 4wd engaged it is normal to get some "crow-hopping" due to the u-joints in the front axle. Those u-joints should be greased occasionally (if they can be) to extend their life, but they will eventually wear out regardless.
If they are originals from 2005, I suspect they could be in need of replacement. If things are binding you might notice your steering wheel doesn't want to return to center on its own very easily.
I am not sure if the '05 uses a sealed bearing hub assembly or if it is similar to my '79 D44 front end where you remove lock out hubs, then a couple spindle nuts and you are able to remove the brake rotor/hub assembly. Once that is removed you can get the axle out to replace the u-joints. I am sure there are some YT videos out there to help with the disassembly process.
***update***
I was looking for the vacuum solenoid that controls the auto hubs to check voltage. From the diagram I looked at, it shows it near the transfer case, but the only thing I see is what looks like the electronic shift on the fly solenoid/system on the bottom of the transfer case. I tried following the vacuum lines from the hubs, but i couldn't see where they went, looks almost like they went behind a heat shield? Im confused at this point. Does anyone know where this solenoid is?
The vacuum resevoir on mine is on the passenger side of the engine bay, not drivers. Unless theres another resevoir specifically for the hubs, but ill have to check that more thoroughly. I'm not seeing the solenoid there, but I'll check tomorrow and update.
Good question, I didn't know so a little google-fu later and found this image...
Sounds like it is in the engine bay, driver's fender area?
ok update: I found the solenoid! It was on the passenger side of the engine bay next to the resevoir. I tested the voltages on the connector, 12 volts in the middle and none on outside 2. Which from what I understand is normal. I'm now starting to think it's a vacuum issue
One or more of the lines are probably cracked or have deteriorated, I don't think I would try to hunt down which one and would just replace all vacuum lines that you find. If one is already leaky the others that may still function won't be far behind. That's probably easier said than done, but would be the best option in my opinion.
On the vacuum solenoid, test from the middle pin to each outside pin, should have something around 100 ohms (can’t remember exactly what it was) they commonly go open circuit and need to be replaced.
On the vacuum solenoid, test from the middle pin to each outside pin, should have something around 100 ohms (can’t remember exactly what it was) they commonly go open circuit and need to be replaced.
ok, i just tested the resistance, according to a snap on service paper I printed, both the left and middle pin should be 45-55 ohms. The left one has 53 ohms, i can't get a reading from the middle. The paper says that if I can't get a reading, or if it's too low, the solenoid needs replaced. But that's confusing considering that's going INTO the soleniod, so how would an input resistance issue mean that the solenoid itself is bad?
There are two solenoids in that thing and they share the middle pin, you should have that 45-55 ohms on left to middle and 45-55 ohms on the right to middle (and 90-110 ohms from left to right). Your testing to see if the wire in that solenoid is burnt out (open, high resistance) or shorted against itself (low resistance). These are electromagnets, so it’s just a bunch of wire wrapped around a cylinder that when energized, move a slug of metal that opens or closed a vacuum port.
You can also power the center pin with 12v and ground each side pin and you should hear a defined click if the solenoid is good, both sides have to work for the solenoid to lock the hubs into 4wd, one side only has to work to unlock it (I don’t remember off had which side is unlock).
oh ok that makes a lot more sense. I checked the resistance between ground and the middle pin and left pin and it was around 15,000 ohms. I'm now trying to locate the 4wd module under the dash but I'm having trouble finding it. i looked under both the driver and passenger side and couldn't see anything like the diagram i was following. any idea on where it is?
Your testing doesn’t make sense, on the 4wd solenoid you need to test resistance between the middle pin and the left pin and then the middle pin to the right pin, this is on the solenoid not the connector on the wiring harness, do not check to ground as the thing is completely plastic and has no connection to ground. The 4wd module is part of the GEM (Generic Electric Module) that is the interior fuse box under the steering column area.
This is the 4wd solenoid you should be testing on the passenger side fender area
Sorry I'm not very good at electric systems. So heres what ive tested so far: resistance between left and right and middle and right on the connector to the vacuum solenoid, resistance left to ground and right to ground, on the connector as the diagram shows, and middle pin voltage. Shopkey pro says to test the connector? Should i have been testing the soleniod this whole time? Here's some photos of the guides I've been trying to follow.
