4wd issue

[Tom Beals]

I have a 2004 xlt with 4wd. I live in the illinois and rarely have to use my 4wd, but we do live about 5 miles out of town and were recently hit by the "polar vortex." I bought this vehicle in the summer of 2010. I have done oil changes and brake pads, but little else in terms of maintenance.



I also know very little about auto mechanical issues - as you can probably deduce from the wording of this post.



So...my 4wd seems to engage fine, but when I hit around 30 mph it starts to feel like I am limited, like something is dragging/rubbing that would not allow me to go much faster. I have read some other 4wd threads, and this happens when roads that are slick/ice packed and does not seem to be an issue of using the 4wd on a dry solid pavement. I am running stock sized tires that are the same size on front and back.



When I switch to 2wd, the feeling remains. It feels as if the dragging/rubbing is limiting speed. One of the times it actually felt as if it was making the vehicle veer to one side, like it was pulling to one side due to the dragging.



This all goes away when I shut the vehicle off and re-start. I can engage/disengage 4wd multiple times during one trip and the dragging feeling is there, but if I turn the key off and leave the vehicle sit, the dragging seems to go away.



I have not pulled off, shut the vehicle off, and re-started. Each time this has gone away I have left the vehicle parked in the garage overnight or in the parking lot at work for 8-10 hours at a time.



I bought this vehicle b/c my old job required travel on country roads to get to work. I ditched my 2wd truck twice over a span of 3 years and decided I wanted 4wd. I have since changed jobs, but we still live outside of town - and I take my daughter to kindergarten. There are probably only 10 - 20 drives per year when I feel 4wd is necessary, but when I go to turn the knob I want it to work. So...any suggestion on what I should have them look at when I take it to the local Ford dealership?



Thanks in advance, this forum is the best.

 

[Yardsale]

Although I cannot tell what is the problem, your write-up is pretty good. If you do take it to a shop, print it and take it with you.



You mention snow ice and dry pavement with regard to other posts you have read

I have read some other 4wd threads, and this happens when roads that are slick/ice packed and does not seem to be an issue of using the 4wd on a dry solid pavement.

Describe the conditions of the road on which you are driving when this occurs. Because the ST has a locked transfer case, the 4WD should not be engaged on a surface that will not allow the tires to slip. If it is, the transfer case will bind, slow you and quite possibly pull to one side or the other. Here's a test:



When you feel this dragging, stop and, without turning the steering wheel, backup about the distance since you first felt the binding. If it is transfer case binding, the dragging should go away. If it does go away, the ST is fine and the driver needs adjustment



You don't note specifically, but I'm guessing that when you park it those times when this dragging goes away, you park it in 2WD, yes?



Without any additional information, WAG #1: Heat build-up, but, oddly, only after engaging 4WD. I guess this because the dragging goes away only after it sits for several hours (after it cools, maybe). I note "oddly" because the front driveline, and associated parts, are driven by the wheels while 4WD is not engaged, I cannot think of a significant additional heat source resulting from engaging the 4WD.

 

[Tom Beals]

Thank you for the info.



Yes, i would select 2wd prior to shutting the engine off.



As for the question about the driving conditions, we had about 10 inches of blowing snow associated with the recent storm and the temps reached the negative teens so no effort was made to salt the roads. My office was closed for 2 days during/after the storm, and this occurred on the first trip following. The pavement was not visible, but I guess I cannot swear that it was terribly slick...about 4 miles of the trip was on a county road (plowed, but not clear), then about 1 mile in town where the roads were similar - plowed but the pavement was not visible as the snow was compacted. The last 3 - 4 miles were on a state highway, but conditions were such that traffic never exceeded 35-40 mph in a 55 mph zone. Some pavement was visible, but it was 75-90% compacted snow covered.



Your explanation makes sense, but I have to admit it concerns me. If I cannot utilize my 4wd in "iffy" conditions such as this, it really does me no good to have the 4wd.

 

[Yardsale]

I speculated that you parked in 2WD because I suspected the problem is transfer case binding. The problem goes away, not because of cooling, but because the ST is no longer in 4WD. I'm going to guess that at home you park in a garage or carport, and at work you park head in, where you have to back out, yes? This backing relieves the binding in the transfer case (like in the test) and allows the shift motor to switch the transfer case in to 2WD.



Does this binding occur all any and all sections of the roads you note or just certain places? It's important to notice where it initially occurs, so that you can pin-point the conditions.



Remember, the 4WD system on your ST is not AWD and you will have to be mindful of changing road conditions to ensure you engage and disengage the 4WD appropriately. This should not be a daunting task (with the switch right there on the dash).