JimmyB1232

I have an 06' 5.4 Screw with 102k miles on it and this last week I was in Montana hunting and it was 26 below the first day and when I started heading up the canyon I put into 4 hi and I could only hear one "click" and I could tell that one wheel wasn't engaged or fully engaging so I stopped and went through the vacuum lines and pulled the VCV and blew into them and disconnected the lines going into the actuator valve (which I replaced 3-4 months ago) and I couldn't pinpoint what was causing the issue. Next day it warmed up to -11 deg and still just got the 1 click going into 4 hi but after letting the truck sit at idle for about 20 min I figured I'd try goin back into 2wd then back to 4 hi and sure enough got 2 clicks and both wheels engaged this time. But since then I'll go into 4 hi and only get the 1 click and sometimes it fully engages. If I only get 1 click and go into 4 low I'll start going forward and once you start slipping you'll feel the front passenger tire almost like it's hopping or almost bouncing a little like the wheel is way out of balance. Both hubs assemblies were replaced this past summer as well as the 4wd actuator, solenoid, and vacuum lines. Issue started as soon as I got up there in the freezing cold and snow. The truck idles normal and engine performs like it should, and when I only get the 1 click there's no grinding noises or issues with the steering but you can tell that 1 wheels isn't engaging properly. Could going through all this snow in the cold weather get moisture in the vent lines then freezing up restricting vacuum pressure? I had a mechanic at a local shop up there tell me it could be the Transfer Case Motor? Is there something else I should check or be looking for? Or could it be my worst nightmare and be something in the differential?

techrep

iTrader: (1)

sounds like you replaced everything else already.. new IWE's / lines and a solenoid.. i think the T-case motor would be next if it were me.. good luck

ford4wd08

[QUOTE="JimmyB1232;3825850"] Could going through all this snow in the cold weather get moisture in the vent lines then freezing up restricting vacuum pressure? /QUOTE]

I think it's this....... Especially if you let it warm up and it seemed to engage.

JimmyB1232

Is there any tricks or something you can do with the vent lines that will help keep water and debris from getting in the lines? And if it's possibly the t case motor can I do the scientific test on it like a starter motor and just give it a couple good taps?

ford4wd08

If you're getting one wheel to lock in and pull, then it shouldn't be your t case. The t case sends one driveline to the front diff. It only has one shaft. It turns, or it doesn't. I don't see how it could only get one wheel to lock in.

I believe I've seen it discussed before about water freezing in the vacuum lines. I would suggest blowing them out with compressed air and possibly insulating them or something. Those are some extreme cold temps. Any
Condensation that is left over that could come from the engine etc being warm would freeze after sitting in those lines.

techrep

iTrader: (1)

he stated he replaced all the vacuum lines.. they should be good

ford4wd08

Doesn't mean they can't get condensation in them. All you need is some humidity and changes of temperature to create condensation.

JimmyB1232

Well after going through the entire system today, I'm thinking the actuator either went bad already (only 3-4 months old), or water/dirt/debris got in and is keeping the spring from releasing the vacuum. (I don't even hear the "clicks" out of it) I had a very, very small vacuum leak coming from a cracked rubber connector and replaced one VCV. Pressurized the lines and had no drop in pressure after 15-20 min. Switched in and out of 4wd and the front left hub wouldn't disengage. Checked the pressure on the lines going into the hub and it had more than enough pressure going to it for it to disengage. With the wheels on the ground and truck running you can spin the passenger drive shaft but not the drivers side. With the truck lifted and in 2wd the drivers side tire rotates.

My buddy told me the actuator just needs to be pulled out and cleaned probably, so my question is, could it really be it just needs to be cleaned out and re-greased? And would it really be worth my time taking it apart and cleaning it, hoping that it works after I put it back together, instead of just replacing it with a brand new one?