It would not be an option and indicate that it can be used in all conditions if it was not intended to be used at all. You also have a warranty, if needed. When the weather turns in a couple weeks, I will be setting mine to 4A as well, great feature!

 

Just to update the thread, my front diff was replaced. It was defective from the factory, both whistling and vibrating under acceleration.

After the new diff was installed, there is no noticeable diff in 2H or 4A.

 

I engaged mine the other day and did not hear anything different, however I was not really listening and the radio up. I will try it again tomorrow if I can remember.

 

I did this back in November, I had noticed a whine, light rotational noise while camping in 4A on some steep washed out dirt roads. When I got back on highway heard the noise. Took it to dealer and test drive a new lariat no noise, tech took out a new KR it made noise so said truck working as designed.

pretty sure today my diff ate it, heard a loud screech noise while accelerating on the highway, now when I slow down whole truck has a vibration and hear a hum. Only problem is I'm 200 miles from home and no dealers open and no way to get home other then drive it and hope it makes it. I was in 2 wheel when it happened but the noise and vibration are define tilt coming from the font.

I was going to try and trade it in this week since I've had constant issues, whatever this issue is will bump me to almost 60 days in the shop, was at about 50 before this, if they truly are taking weeks to get parts, I will be initiating a buy back, I'm tired of driving a loaner car while my truck sits in the shop. I. Lucky I get a loaner, I know some of you haven't, but it sucks paying the payment on a 50k truck and spending 2 months out of 10 driving a base focus loaner car.

 

Sorry to hear . Mine did end up getting replaced in two days thankfully. After my dealer told me a multi week wait, I PM'd Chad the service rep on here. He got the regional folks involved and my dealer had the part the next day. They took a diff off the assembly line. With all the East Coast snow I used 4A and 4H a good bit, no issues and back in 2H everything sounds normal. I'd highly recommend reaching out to Chad.

 

Question about turning while on 4H. I have a 2015 FX4, when i drive it on 4H and make a turn the truck wants to stop from so much friction i guess. I figured it might have been normal since my first time trying it the road was dry. Today we got 4 inches of snow and I got the same while driving on snow. When backing out of a parking spot the truck literally stops when backing while the wheel is turned, and required some gas to make it move again. Is this normal, this is my first 4x4 truck/car so i dont have anything to compare to.

 

Yes, is is normal. You DO NOT want to use 4L or 4H on dry roads or parking lots or anything other than mud, grass, snow,etc. ala loose terrain or the system will bind and can be damaged.

 

Last question. Is there a speed limit for driving on 4H?

 

Yes, something like 60, but it will disengage automatically at the predetermined speed regardless.