bad bad day.

towing from maine to virginia then out to utah and at 60mph towing a large TT my 4x4 lights started to blink on the dash. 35k trouble free towing miles til now.

its a 2008 Super Duty 250, crew cab, 5.4gas automatic with Tow command, 4x4 SnowPlow Package (so auto hubs), all stock, even running the factory contis for rubber still. its the XLT model, air, cruise, power seat driver side,

the 4x4 engaged while towing on the highway, i got off the next exit after slowing down to the 45 min. speed and played with the 4x4 hubs and switch til it unlocked.

back on highway it was 100 miles no problem then 4x4 LO startedblinking and the truck started stalling, at 45 mph it ENGAGED into 4x4 LO and stalled the truck.

restart, more playing with hubs and swtiches, it drove fine back to the nearest campground sign I saw.

called three dealers only one had service hours today, said he would be guessing at the problem, it might take three days to find the issue, if they can make it happen again at all.

dealer suggested I take it back where I bought it. (bet if it wasnt under warranty he would have helped me) then I called the dealer i bought it from anbout 12 hours away from here and manager advised I have it fixed where I am, they had a whole bunch of people quit no idea when he can get me in. worse was he had no suggestions for what to do to avoid it happening again on way to a dealer.

Anyone have an idea on what I can un hook? un plug? a fuse to pull? to make sure the 4x4 wont engage on me while towing on the highway til I can get to a dealer who will service this?

is there a fuse that I can take out or a vaccuum line I can take off?

thanks all! I'll be sittin here

 

You could remove the fuse, or disconnect (and tape) the wires that go to the transfer case shifting solenoid....be sure it's in 2 high before you do it though.

 

Look in your owners manual for the right fuse to pull. It should be in there. Good luck.

 

thanks guys< i am hunting through the fuses and owners manual now.

 

Concur with the above...your bigger problem is going to be in the ECU as it is what will not allow the truck to go into 4L without it being stopped, and in neutral. Usually, apparently.

 

well thats where I am too.

I pulled 3 fuses that according to the manual all say 4x4 module. BUT there must be one I am missing or something is big time screwed up, with those fuses out, I can still flip the switch into 4x4 LOW with tranny in Neutral and it WILL go into 4 low, so what am I missing?
reverse sensing and all that is out, as some of them are in those other 3 fuses I pulled but I can live with that.

I think the big problem is why is the transfer case allowing the 4x4 LOW range to engage while moving and tranny in gear?

is there some sort of interlock that I can check? maybe its busted and letting the 4x4 low lock in ??

thanks all!

 

I would put the fuses back in, and then unplug and tape off the two wire connector on the transfer case, until you can get it looked at. That goes to the shift motor and it can't shift if it's unplugged.

All the interlocks are programmed into the 4WD control module. I'd guess that module is bad if it's doing things by itself.

The other concern you may have at this point is that if the transfer case shifted into low at 40 MPH, it may have caused some internal damage that won't present itself until some time in the future.

 

if your truck shifted itself into 4Lo at 40+ mph I'd think your transfer case would throw gears through the floor! That or your engine would start spitting rods and floating valves. Stalling in low doesn't make any sense at all. Did it engage 4hi and 4lo at the same time and bind things up?


at the very worst, just unlock your hubs, stick it in 4 high, and get it where you need to go...

 

can't unlock the hubs as it is ESOF. I would look for the wires to the transfer case and tape them/remove them.

 

can anyone post a photo or diagram where these wires are? I am crawling around under there and can't find a single wire or connector, I can not post a photo right this second, its all I can do to get an internet connection down here.

at this point I am only trying to get this TT back the 700 miles to VT and then this truck to a dealer, I think the transfer case is screwed up, if its not I dont know how it isnt, all four tires locked up til it stalled, no different than throwing your standard tranny on a shift from 4 to 5th and instead hitting 1st, which isnt suppossed to go either, but thats what it looked and felt like, pretty hairy with 12k behind you on I 64 rush hour.
thankfully we stayed straight.]

I cant find this connector or wires on teh transfer case, more help please! then I'll let you fellas be for the weekend....at least until I am SOL on the roadside and need a FTE buddy to tow my TT back to VT for me. Then you'll hear from me again. Alot.

 

If you can't unplug the vacuum lines to them, you can always take the locking rings out so they can't engage.

 

Wow,,,seems all most impossible that it could even go into 4x4Low at 40 mph,,,without a total ***-a-part of the transfere case,,??
The tranny seems OK?
My truck is a manual hubs and T-case truck(So glad it is),,,But there should be a plug with wire's on it on the transfer-case (center of the truck, behind tranny) not sure if it would be on the front or backside of the T-case,,,Good Luck man!

 

yeah, since the transfer case doesn't ahve synchros it should have just gone into neutral and made all kinds of awful grinding sounds... I believe they are straight toothed sliding mesh gears that should have been rotating at VERY different speeds.

 

so 'no' to the photos?

there are no wires or connections that I can see on the transfer case at all, there is a large shield across it and I can't reach the top of the case because of the shield.

anyone know which of the 4 fuses control the 4x4 switch? I can't narrow it down more than there are 3 fuses in teh bank that all say 4x4 module, and a fouorth fuse in the engine compartment in the high volt section that is in position 13 that is also labeled 4x4 mod.

all 4 out and I can engage 4x4 high, so I am missing something, there isn t a fusible link for the 4x4 is there?

couple PMs sent to those who seem to know what they're tlaking about, respond if you would thanks!

 

You said you were towing to VA.. Where are you exactly?
Maybe there is someone close by who could help or refer you to someplace close by...