Auto 4wd, leave it on?

[Nj921]

This will probably have many different answers, but I'd like to hear some opinions. Mechanics and techs, please chime in!

Does anybody keep their truck in Auto 4wd? Is that not the purpose of auto? The truck senses slipping, and puts power to the front wheels. I always did in the past and never had an issue, granted my previous trucks had the horrible goodyear tires that slipped on dry pavement even without getting on it. Now that I have bridgestones that actually grip the road, I mainly just use the auto in the rain, unless I forget to turn it off. Now, even when wet outside, if I go around any turn it binds up. Bad. Seems like the auto is in fact full 4wd in my truck.

From the manual... "4WD AUTO Four-Wheel Drive Auto High Range — This range sends power to the front wheels automatically when the vehicle senses a loss of traction. This range is used during varying road conditions."

 

[SpeedyV]

Only if you want to burn extra fuel...

 

[VectorZ]

If the roads are icy or slippery sure, otherwise no. I don't think it will hurt anything, but you will burn more gas.

 

[Neurobit]

It won't hurt anything. I had mine for a few days on 4WD Auto right after I bought it. Used it in wet and dry pavement w/o any issues (as designed).
Like Speedy said, you may have less MPG (although negligible), due to parasitic loss in the front diff.

 

[wirles]

If I read it correctly, he is binding even when he isn't slipping as if it was locked in 4-High. If that is the case, I would take it into the dealer to have the 4WD checked.

 

[Nj921]

Wirles, You are correct Auto in fact seems to be locked. I'm wondering if there is a sensor that is "detecting" slipping, even though it's not. It'll have to go in, but the problem is most dealers in Michigan will tell you their heavy mechanics are 3-4 weeks out. Great timing considering the snow can hit any time here.

 

[GATORB8]

Wirles, You are correct Auto in fact seems to be locked. I'm wondering if there is a sensor that is "detecting" slipping, even though it's not. It'll have to go in, but the problem is most dealers in Michigan will tell you their heavy mechanics are 3-4 weeks out. Great timing considering the snow can hit any time here.

In 4WD AUTO, the front axle and hubs are engaged, only the transfer case is not sending power to the front, this may explain what you're experiencing. You're binding does sound like you are in 4WD High, but I'd be surprised if your tcase isn't shifting out of 4 without an error.

From the manual:
This electronically shifted transfer case is designed to be
driven in the two–wheel drive position (2WD) or fourwheel
drive position (4WD AUTO) for normal street and
highway conditions on dry hard surfaced roads). Driving
the vehicle in 2WD will have greater fuel economy benefits
as the front axle is not engaged in 2WD.
For variable driving conditions, the 4WD AUTO mode can
be used. In this mode, the front axle is engaged, but the
vehicle’s power is sent to the rear wheels. Four-wheel drive
will be automatically engaged when the vehicle senses a
loss of traction. Because the front axle is engaged, this
mode will result in lower fuel economy than the 2WD
mode.

 

[Nj921]

Thanks Gatorb8, very helpful. I am going to check with the dealer and hopefully get it in sooner rather than later.

 

[RamCares]

Thanks Gatorb8, very helpful. I am going to check with the dealer and hopefully get it in sooner rather than later.

Nj921,

We are sorry to hear that you have a concern with the 4WD in yout truck. Please let us know if you need additional assistance while your truck is in service.

Darlene
Ram Social Care Specialist

 

[Mason1217]

So if auto 4wd engages when it senses slippage, what happens if you have auto 4wd on and traction control off?

 

[GATORB8]

So if auto 4wd engages when it senses slippage, what happens if you have auto 4wd on and traction control off?

Should still see the slip and activate the front axle, TC is just the braking function that brakes the slipping wheel.

Now, if you don't have LSD, TC off and one of the front wheels is also spinning, you could have 2WD Auto in that situation. (TC off may still allow some governance, though).

 

[rmlephiew]

Thanks Gatorb8, very helpful. I am going to check with the dealer and hopefully get it in sooner rather than later.

Any update on this? Did you end up taking it to the dealer? I tried 4WD AUTO twice today in slightly rainy conditions and also experienced what felt like a little binding when turning.

 

[Nj921]

I havent taken it in yet. It is definitely not right though. I've had a couple other issues come up that need to be addressed at the dealer too, and they are weeks out. I will update when I get a chance to take it in. Or if you beat me to it, let me know!

 

[zenithgarfunkel]

Any update on this? Did you end up taking it to the dealer? I tried 4WD AUTO twice today in slightly rainy conditions and also experienced what felt like a little binding when turning.

I havent taken it in yet. It is definitely not right though. I've had a couple other issues come up that need to be addressed at the dealer too, and they are weeks out. I will update when I get a chance to take it in. Or if you beat me to it, let me know!

I'm also experiencing this issue and my truck is currently at the dealership for troubleshooting. Multiple people have driven it at the dealer and we have compared it to other trucks on the lot. There is definitely something wrong, but so far it has not been diagnosed. 4WD auto and 4WD hi are effectively the same on my truck. Any word on what the cause is?

 

[rmlephiew]

I'm also experiencing this issue and my truck is currently at the dealership for troubleshooting. Multiple people have driven it at the dealer and we have compared it to other trucks on the lot. There is definitely something wrong, but so far it has not been diagnosed. 4WD auto and 4WD hi are effectively the same on my truck. Any word on what the cause is?

I haven't had it looked at yet, but I am interested in hearing what they figure out on your truck. Hopefully they figure it out and it's an easy fix.

 

[Nj921]

I’m picking mine up from the dealership tonight. I took a stack of TSBs with me that all pertained to issues in my truck, one of which being the 4wd issue. (13 in total, plus 2 recalls) They said they did some repairs, but other repairs require parts on backorder, and it’ll go back in when they arrive. I will try to get more info this evening. This truck is a nightmare.

 

[Gondul]

This truck is a nightmare.

At least it won't catch fire by going through a car wash!

Honda's pickup trucks recalled because they can catch fire from car wash soap

 

[Nj921]

Lmao that’s the best one I’ve ever heard. That’s worse than the f150s catching fire from the seat belts!

 

[Nj921]

Front axle is the culprit. Of course it’s on backorder, so I’ll have to deal with it another month. Part number: 68349702-ad. It is in fact the technical service bulletin issued here.
https://www.dropbox.com/s/vsawlxeyhxmfoyc/Front Axle Noise While in 4WD Mode.pdf?dl=0

 

[riccnick]

Wow!