So now that it's winter and I've started to use my 4x4 when I drive my 2017 F350(Which is rare as I'm usually in my Mechanic Rig) anyways when doing anywhere from 40-110km/h in 4wd auto, I notice an extremely audible howl as soon as I let off of the throttle. Just curious if anyone else has experienced this? H

ere is a few things I have noticed

-Happens only in 4wd, the second you turn it back to 2wd with no throttle the sound is completely gone.
-Sound will stay on when changing from 4wd to 2wd if you are putting any sort of throttle but as soon as you let off and depress throttle again the sound is gone
-Happens regardless if hubs are in Auto or Locked
-Seems to be a resistance when in 4wd and coasting but in 2wd coasts freely (Exhaust brake off obviously)

This howling sound is extremely pronounced and is not subtle in the least bit.

Dropped it off at the Dealer for the fuel tank TSB and to look into it and well surprise surprise the techs couldn't find anything and just said "It's your 4wd disengaging or its your oversized tires making road noise" I promptly asked her to read the name on the account (Titan Wrenchworks) which she then had the self realization that I'm a Journeyman Mechanic and it's going to take a lot more than telling me my tires are making the noise. I'm taking the truck back home for Xmas but when I get back I'm going to take the service manager for a drive with me and drive him around until he pulls his head out of his *** and admits there is something not right.

I've owned a 2008 F350, a 2014 F550, Countless Rams from 05 to my current 2015 Ram 5500 and none of them have ever had an audible 4wd system. It almost sounds as if the exhaust brake is active when coasting in 4wd auto(which it is off obviously for diagnosis purposes)

My suspicion is either a loose chain inside the transfer case or an improperly set up front differential but who knows. I may drop the front diff fluid and see if there is any pixie dust floating in there.

Truck has 11,2xx Km's, is completely stock other than a set of Toyo Open Country AT2 on factory wheels 35x12.50x20 that were on the truck when I bought it brand new from the dealer.

 

It sounds like an improper gear set up in the front end. I’d open the diff case, check backlash and pattern, especially on the back side of the ring gear.

 

yeah my thoughts exactly, only thing stopping me is I wrench all day, last thing I want to do is go digging in my brand new truck when I have warranty for that exact reason... might try and get it into my dealer when I go back home time depending.

on the plus side with the Tank TSB done I have like 160km more DTE than I did before!

 

There have been a few reports about the 17's making this noise exactly like you are describing. For the 17's and up it is a new transfer case.


So far no one has pin pointed what is making it.


It would assume it is the chain running on the gears inside the case.

 

I have a weird gear whirring sound on my truck. It can be heard from 25 MPH up. 2wd or 4wd. It is pretty subtle at this point though, but does seem to be getting slightly worse as the miles go by. It started around 9K miles, have 11K now. Just had it to dealer last week, was told it is "normal".
In 4wd, coasting, as mentioned above, I do have a much louder groaning sound that I've never noticed on any previous trucks.

If I were a betting man, I'd say it is the transfer case. I wonder if borg warner botched this new design?

 

This is the 3rd recent thread on this. I think the consensus is that the new transfer case makes a lot more noise than it should. Mine hums, none of my other SD's ever did, I know I don't like it.

 

More recent threads:
https://www.ford-trucks.com/forums/1...elerating.html

https://www.ford-trucks.com/forums/1...se-in-4wd.html

https://www.ford-trucks.com/forums/1...ing-noise.html

 

Mine is the first thread posted and I have to make a correction on that as I was on 3 hours of sleep when I typed it. I have the same exact symptoms as the OP of this thread. As soon as I release the throttle, I hear the whine/howl. If this is normal shame on Ford as this is the loudest 4wd system I've ever experienced. Like I had mentioned before, it's much louder than the 4wd on my 86 F-150. Given the lack of sound deadening material on my 86, that's crazy.

 

I was about to post something about this myself, for work I've driven about 15 different 2017 trucks gas, diesel f-250 through f-550 and ALL of them have had a almost marbles in a can type sound when coasting from 55-35mph and if you get back on the gas it goes away.

My 2002 and my 1991 are both dead silent so this seems very concerning to me! Seems to me there is an issue.

 

Mine's a '17 and has identical sound as described by OP in this thread.

 

I have had my 2017 since last December. I drove it home brand new 450 Km in a snow storm at -20. Pretty much all in 4H, varying speeds depending on conditions, the last half of the trip pretty slow, cold and white out conditions.

My truck now has 21,000 km on it, I have to say, for comparison, the noises I hear accelerating, at speed or coasting in 4*4 are very mich the same as my 2005 diesel. I hear some tire noise, u-joint noise, perhaps gear noise and transfer case. I can feel it somewhat similiar in the floor boards, especially under hard acceleration. Sometimes under deceleration.

I would definately have your dealer examine and have it on record, that's the safe bet. But, I doubt they will find much. I checked my engine, transmission, transfer case and both axle oil levels shortly after getting home just to be on the safe side. I also check what they have done after each service.

 

What do you mean by 4x4 auto? I wasn't aware that the new Superdutys had that option.

 

Same issue, currently at Jerrys Ford getting looked at

 

Mine makes some noise. Howling, not a “rocks in a can” noise one person mentioned. To me it sounds like straight-cut gears, sort of like a lot of reverse gears in manual transmissions. Anyway, I wonder if any of this is related to the fact that these new xfer cases use Mercon LV.