Help with 4x4 auto

[OldExpy]

I am a new owner of a 2016 Expedition Limited. Before my warranty ran out, I was trying to check that the 4x4 system was working ok. Since the roads were pretty dry I put it in 4A, which the manual says "is appropriate for all on-road driving conditions, such as dry road surfaces, wet pavement, snow, or gravel".

In my old 2003 Expedition I could put it in 4A and forget that I had done that. I never heard or felt the car unexpectedly shifting into 4 wheel drive unless needed. When I was testing the 2016, I could both hear and feel the car engaging the front wheel drive at random moments.

I took the car to the dealer explaining that when in 4x4 auto, the car seemed to inappropriately engage the 4 wheel drive and it was making grinding noises that I was not familiar with. Two weeks later, I got the car back and the following had been done. They replaced the front left hub assembly. Then, when they tested it, they didn't like a noise they heard and they also replaced the front differential bearings and seals and both front IWE actuators.

Now that I have the car back, it still seems to randomly engage the front wheel drive. I would not normally drive in 4x4 auto when on paved roads with dry surfaces. But that was my choice for testing it. I drove it in 4x2 without any surprises, but when it was in 4x4 auto doing residential, slow driving with some slight uphill and downhill it would randomly engage. I could understand it happening once (maybe there was a bit of gravel on the road), but it seemed to happen multiple times, consistently.

When I talked to the dealer about it he said the current system uses vacuum actuators and that they are more sensitive (than my old Expedition) and that it is working properly. He also said don't drive it in 4x4 auto on dry surfaces. In the end, I rarely use 4x4 auto, but am I crazy for thinking it is not working correctly.

Any owners that use 4x4 auto regularly who can share their experiences? The noise when it engages is unsettling.

Thanks for any help.

 

[B-McD]

On mine I can definitely tell when I put it in 4A. You can feel more stuff moving in the driveline. But 90% of my driving is in 2H. Maybe if it's raining really hard I may put it in 4A. In snow - and I mean driving on unplowed streets, etc., I use 4H. 4A if it's a bit slushy and the plows have been out. Dealer is wrong about 4A on dry roads - 4H or 4L on dry roads not recommended, you are fine in 4A. Not real different in concept to most AWD crossovers - applies torque when it senses slippage, otherwise it's mostly 2WD. You can bring up that torque display showing drive to the various wheels. I think it's in the off road section of the display. (you can see I don't use it much)

Enjoy your 2016! Mine has been pretty trouble free for 65k miles.

 

[OldExpy]

I have the same use pattern... most of the time in 2H. If it's snow I put on 4H. Slushy 4A. I was just startled that in 4A on dry roads it was engaging/disengaging with no obvious slippage.

 

[99WhiteC5Coupe]

I am a new owner of a 2016 Expedition Limited. Before my warranty ran out, I was trying to check that the 4x4 system was working ok. Since the roads were pretty dry I put it in 4A, which the manual says "is appropriate for all on-road driving conditions, such as dry road surfaces, wet pavement, snow, or gravel".

In my old 2003 Expedition I could put it in 4A and forget that I had done that. I never heard or felt the car unexpectedly shifting into 4 wheel drive unless needed. When I was testing the 2016, I could both hear and feel the car engaging the front wheel drive at random moments.

I took the car to the dealer explaining that when in 4x4 auto, the car seemed to inappropriately engage the 4 wheel drive and it was making grinding noises that I was not familiar with. Two weeks later, I got the car back and the following had been done. They replaced the front left hub assembly. Then, when they tested it, they didn't like a noise they heard and they also replaced the front differential bearings and seals and both front IWE actuators.

Now that I have the car back, it still seems to randomly engage the front wheel drive. I would not normally drive in 4x4 auto when on paved roads with dry surfaces. But that was my choice for testing it. I drove it in 4x2 without any surprises, but when it was in 4x4 auto doing residential, slow driving with some slight uphill and downhill it would randomly engage. I could understand it happening once (maybe there was a bit of gravel on the road), but it seemed to happen multiple times, consistently.

When I talked to the dealer about it he said the current system uses vacuum actuators and that they are more sensitive (than my old Expedition) and that it is working properly. He also said don't drive it in 4x4 auto on dry surfaces. In the end, I rarely use 4x4 auto, but am I crazy for thinking it is not working correctly.

Any owners that use 4x4 auto regularly who can share their experiences? The noise when it engages is unsettling.

Thanks for any help.

I have a 2015 Ford Expedition Limited 4x4 - purchased new and never wrecked or damaged (other than a windshield).

While under the new-car warranty, the drivetrain would make a clacking or growling noise when going uphill, just before the transmission would downshift (engine at low vacuum).

I took it to the selling dealer, and they claimed they checked everything and could not duplicate the noise. On the way home, the noise recurred, when going up a hill (I live in a hilly area, but not mountainous).

I checked online and quickly found a Ford TSB which stated to consider the root cause of the issue to be a defective vacuum check valve for the 4WD system. The TSB instructed the dealer to replace the valve without testing it. If the problem continued, they were to check the vacuum lines and connections.

I bought the valve (about $10 at the dealer), and replaced it in five minutes. That eliminated the noise and odd feeling.

I do not have a copy of the TSB to post, but could look up the part number fo you tomorrow if you wish.

When I bought the valve at a Ford dealership (not the selling / servicing dealer) - the part’s guy said he kept them in stock as they used a lot of the valves.

Ford has issued and revised numerous TSB’s for the third generation 4WD engagement / disengagement system. I’m convinced it is a poorly designed and manufactured system, that is rife with problems.

PS - I live in the Midwest’s snow belt and use the 4A position anytime it is raining and/or snowing or sleeting. It is not unusual to have a 1-2 inch rainfall in 24-hours several times a year, in addition to heavy spring rains. I have used the 4H in deeper snow.



EDIT: Here is a link to one of the latest TSB’s regarding this matter. It has the information about the IWE check valve part, and a picture of its location.

One or more prior bulletins simply stated to replace this check valve.

EDIT #2: Here is the link: https://static.nhtsa.gov/odi/tsbs/2018/MC-10149748-9999.pdf

 

[Langer]

I pretty much have my 2017 in 4A the whole winter here in Chicago. I can definitely tell a difference between 2h, especially in turns (the vehicle feels like it’s pulling through the curve, rather than pushing, which makes sense, because it is), but I wouldn’t say I feel the “tug” you’re experiencing.

 

[jeff kushner]

I have 112K on my '17, same as your '16 in every way other than a switch or two.

I drive in 4A at all times, unless I want to use 4lo or 4hi but since we haven't had any real snow since I got it, it's only been in 4hi once coming to work one morning.

The way I feel is that I didn't spend $53.9K otd to not use some of my vehicle features. My gas mileage since new (never have reset one of the trip odometers) is 18.5...............and we live in the same State. I also have a bad habit of playing let's out-corner the "sports" cars on exit ramps and the 4wd kicks in pretty seamlessly when I get a little sideways getting onto Route 97S at 4:15 in the morning. The amazing thing was that my original tires lasted 92 or 94K! I did direct replacements. Not the quietest but a "known".

I also experienced what I thought was a front end issue at 35K and even ordered the replacement check valve and a couple of other parts I never installed. I ended up draining the rear end, refilling with Mercury lower end juice and the Ford 4oz additive at 38K and the problem vanished! I would have bet my ex-wife's life that the noise was coming from the front! <LOL>

Good luck my (Old) friend, lol

jeff

 

[Frank Wilson]

I have a 2015 Ford Expedition Limited 4x4 - purchased new and never wrecked or damaged (other than a windshield).

While under the new-car warranty, the drivetrain would make a clacking or growling noise when going uphill, just before the transmission would downshift (engine at low vacuum).

I took it to the selling dealer, and they claimed they checked everything and could not duplicate the noise. On the way home, the noise recurred, when going up a hill (I live in a hilly area, but not mountainous).

I checked online and quickly found a Ford TSB which stated to consider the root cause of the issue to be a defective vacuum check valve for the 4WD system. The TSB instructed the dealer to replace the valve without testing it. If the problem continued, they were to check the vacuum lines and connections.

I bought the valve (about $10 at the dealer), and replaced it in five minutes. That eliminated the noise and odd feeling.

I do not have a copy of the TSB to post, but could look up the part number fo you tomorrow if you wish.

When I bought the valve at a Ford dealership (not the selling / servicing dealer) - the part’s guy said he kept them in stock as they used a lot of the valves.

Ford has issued and revised numerous TSB’s for the third generation 4WD engagement / disengagement system. I’m convinced it is a poorly designed and manufactured system, that is rife with problems.

PS - I live in the Midwest’s snow belt and use the 4A position anytime it is raining and/or snowing or sleeting. It is not unusual to have a 1-2 inch rainfall in 24-hours several times a year, in addition to heavy spring rains. I have used the 4H in deeper snow.



EDIT: Here is a link to one of the latest TSB’s regarding this matter. It has the information about the IWE check valve part, and a picture of its location.

One or more prior bulletins simply stated to replace this check valve.

Link?

 

[99WhiteC5Coupe]

Link?

Sorry.

Here is the link: https://static.nhtsa.gov/odi/tsbs/2018/MC-10149748-9999.pdf

 

[OldExpy]

Thank you to everyone who replied. I drove the car around quite a a bit this morning, with the off-road view available watching the power distribution over the four wheels. In the context of trying to understand how the 4x4auto was working it helped me understand the sounds and the pattern of engagement/disengagement.

 

[07navi]

Driving in 4 auto all the time is a bad idea. The front components get more wear and it lessens MPG's. It's not even good for wet roads but helps on snowy roads but you can usually use the real 4wd then anyway. I think they did away with it on some later models also.

 

[Plati]

Both my 2003 and my 2014 I drive in 4A 99% of the time. I have no reason to drive in 2H to save gas which is the reason people normally give to do that. I do put it in 2H sometimes just for the heck of it. I cannot tell any difference in normal driving and I never have heard any noises like you mention. Same with the 1999 I previously owned. In special situations I also use 4H and 4L. Thats 400,000 miles of experience in 3 Expys.

Dealer telling you not to use 4A on dry pavement ... either there is a misunderstanding or he is way off wrong and does not know what he's talking about.

My understanding is that the front is "engaged" (as you phrase it) once ... When you turn dial to 4A and stays that way. Power is applied as required by the Transfer Case in 1% increments from then on, the 4WD doesn't connect and disconnect.

 

[07navi]

So why do you do that?

 

[Trainmaster]

The A4's fine to use all the time, according to the owners' manual and many years experience. I can tell when I have it selected but there's no clunking, grinding or chattering in turns.

If yours is misbehaving, there's something wrong with it.

 

[vincentrose]

Both my 2003 and my 2014 I drive in 4A 99% of the time. I have no reason to drive in 2H to save gas which is the reason people normally give to do that. I do put it in 2H sometimes just for the heck of it. I cannot tell any difference in normal driving and I never have heard any noises like you mention. Same with the 1999 I previously owned. In special situations I also use 4H and 4L. Thats 400,000 miles of experience in 3 Expys.

Dealer telling you not to use 4A on dry pavement ... either there is a misunderstanding or he is way off wrong and does not know what he's talking about.

My understanding is that the front is "engaged" (as you phrase it) once ... When you turn dial to 4A and stays that way. Power is applied as required by the Transfer Case in 1% increments from then on, the 4WD doesn't connect and disconnect.

Yes you are correct about the front being "engaged" but while the front is engaged, the front axle shafts, the front differential and the front driveshaft are all engaged to the front wheels and turning. This is mechanical resistance, which uses energy, and on dry pavement it is unnecessary, and will use more fuel in doing so, causing your mileage to drop 1-2 mpg, and of course unnecessary wear and tear on these components as well. Which is why there is a front wheel hubs disconnect on the IWE's so that the front driveline doesn't have to rotate when its not necessary and thus saving that extra fuel by not having that unnecessary mechanical resistance.

 

[Plati]

Yes you are correct about the front being "engaged" but while the front is engaged, the front axle shafts, the front differential and the front driveshaft are all engaged to the front wheels and turning. This is mechanical resistance, which uses energy, and on dry pavement it is unnecessary, and will use more fuel in doing so, causing your mileage to drop 1-2 mpg, and of course unnecessary wear and tear on these components as well. Which is why there is a front wheel hubs disconnect on the IWE's so that the front driveline doesn't have to rotate when its not necessary and thus saving that extra fuel by not having that unnecessary mechanical resistance.

Yes. Pretty much totally agree & you mention the second and third reasons to run in 2H. I have done some unscientific tests and my experimentation plus my thought process tells me it is more likely to be under 1 MPG but I can't stand behind that with other than gut feel. I also don't think the wear would be substantial, also gut feel. I want the traction for unexpected rainstorms that I encounter without remembering and switching so I just leave it in 4A taking the economic hit. Potential safety over economy. Good points you have!

So when in 2H .. front wheels are disconnected from side shafts spinning freely along road and everything in front of Transfer Case to wheels is also not spinning? Not sure I knew that last part. But it makes sense that Transfer Case will loosen up and not send power to front in 2H. Thanks

I just drove 1500 miles down East Coast in 2H cause when I left home I thought I would try it. Its zactly like 4A did not notice any difference. 17.5 MPG. I think I'll ManUp run in 2H and switch to 4A as needed?

 

[07navi]

vince is right in all areas. It is zero safer on dry pavement and your front diff, u-joints, t-case are working needlessly. It's a lose/lose scenario. It's not even safer on wet pavement unless maybe you floor it at stoplights in the rain.

 

[vincentrose]

So when in 2H .. front wheels are disconnected from side shafts spinning freely along road and everything in front of Transfer Case to wheels is also not spinning? Not sure I knew that last part. But it makes sense that Transfer Case will loosen up and not send power to front in 2H. Thanks

I just drove 1500 miles down East Coast in 2H cause when I left home I thought I would try it. Its zactly like 4A did not notice any difference. 17.5 MPG. I think I'll ManUp run in 2H and switch to 4A as needed?

Yes, you are correct, the IWE's (Integrated Wheel Ends) are vacuum controlled and disconnect the wheel hubs from the half shafts, and thus the Half Shafts, Diff, and driveshaft doesn't rotate while in 2H mode

 

[07navi]

Right again, there is

Yes, you are correct, the IWE's (Integrated Wheel Ends) are vacuum controlled and disconnect the wheel hubs from the half shafts, and thus the Half Shafts, Diff, and driveshaft doesn't rotate while in 2H mode

Right again, there is no reason for anyone to drive in 4wd auto unless the road is snowy, icy, or some other rarely needed occasion.

 

[lbv150]

When my wife drives in or right after a winter storm, I just tell her in put it in 4A....much easier for her and nothing will get screwed up on the truck. I never use 4A as I know when to use and not to use 4H. I would prefer Warn manual locking hubs and a lever 2H N 4H 4L like in my pickups. No need for 4A...

 

[Plati]

Right again, there is

Right again, there is no reason for anyone to drive in 4wd auto unless the road is snowy, icy, or some other rarely needed occasion.

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