Hi Scotty,
I have 2019 F150 FX4, first truck I owned and first vehicle with 4WD.
today I wanted to try the 4WD and I shifted the truck in the parking lot to 4WD High. I drove it for a mile maybe with speed 10-20 mph. I was hearing a very loud noise grinding specially when I was turning. After that I stopped the truck and turned back to 2WD and the grinding sound gone.
After this accident I read the manual and found that Ford added a note that we can not use 4WH or 4WL on dry paved road otherwise it will damage the components.
my question, what is the chance that I damaged the 4WD components or any drive shaft?
thanks
Driving straight ahead with the 4WD engaged on pavement would not have been a problem, the problem is making turns. The issue is that with a part-time transfer case that has no center differential you put a lot of strain on the drivetrain when turning on dry pavement due to different rotational speeds of the front and rear tires. Something has to give - if you're lucky one of the tires loses grip and slips, if unlucky something in the drivetrain breaks. (I have a part-time transfer case in my old Jeep and the rule I follow is to only put it in 4WD either off-road or if the road is slippery; snow covered or enough rain that the rear tires break traction.)
If you didn't make many turns you're probably OK, just be sensitive now to any clunking or looseness in the drivetrain and have any issues repaired ASAP. And, most importantly, don't do that again!
Thank for your assistance. I wants to add the following comments:
1) today I drove the truck around 100 mile with no issue.
2) I stopped at Ford dealer and I explained what happened, they told me it should be fine and there is no reason to inspect it again and may cause a damage. They told me this is a strong truck and some times they test the 4WD system at the dealer parking lot. I asked again to do at least visual inspection but they refused again.
If there are no clunks or vibration you should be fine.
Thanks again. Is the dirt or grass road consider off-road and possible to use 4WD High on it?
Yes, any surface where the tires can slide/slip to take up the difference in tire speed will do. (Dirt, grass, gravel, snow, even heavy rain.)
I would say chances are 100%. That's what the manual says right?
4WD is for when you need traction, not dry pavement.
Why would you drive for a whole mile when you heard grinding? :silly:
Another reason why you should read the owners manual front to back, over and over, as soon as you get a different vehicle.
💯 agree with you
The problem is that manuals today are so voluminous. A friend of mine a few years ago bought a new Subaru Outback and the manual for the danged radio was hundreds of pages long.
I noticed that owner's manuals are running over 600 pages these days. But, when you lay out $40,000 for a vehicle, you cannot obfuscate your responsibility to know how it works. Just go to the index and look it up.
Chuck laid out really well why not to drive 4wd on dry pavement. The other reason not to is that there is no way to perfectly match the front and rear differential in lash, tooth contact pattern or actual ratio. They may both be 3.73 but they will always turn at slightly different speeds given the same input, especially when turning.
Usually about 400 of those 600 pages is devoted to the entertainment system. 100 pages to tell you not drink the coolant and other such warnings for idiots. The parts that really matter are the remaining 100 pages.
Your Ford manual is correct in regards to when 4 wheel drive should be used.
That being said, I'm guessing the noise you were hearing while going straight was probably normal. Every part time 4x4 I've been in or currently own makes a noise while engaged. It could be interpreted as 'grinding'.
I'm guessing, but the grinding sound you heard while turning is due to the front axle not having a limited slip setup as you probably do in the rear axle. While turning the front wheels were turning at different speeds creating the sound. On dry pavement, they would be 'fighting' each other due to the distance as you turn. The inside wheel would travel less distance than the outside wheel if that makes sense.
For that short amount of distance and low speed, I don't think you caused any damage.
Thank for your assistance. I wants to add the following comments:
1) today I drove the truck around 100 mile with no issue.
2) I stopped at Ford dealer and I explained what happened, they told me it should be fine and there is no reason to inspect it again and may cause a damage. They told me this is a strong truck and some times they test the 4WD system at the dealer parking lot. I asked again to do at least visual inspection but they refused again.
600 pages? Really?
Holey Moley!
My 95 Olds has about 4 pages for the radio, a dozen or so safety tips and the rest is good to know stuff.
that's progress for ya!