OSCILLATING HUMMING NOISE/VIBRATION AT HIGHWAY SPEEDS, GOES AWAY IN 4H

[RunningJerk]

Update: my dealer had their tech drive my bronco 3 different times before they did what I said they needed to try, which was to shift from 2 to 4H and back. Even if it isn't making noise in 2, shifting to 4H and back causes the noise and vibration every single time. The tech said he thought it could be a number of things. He said it could be the leveling kit that's throwing things off. I explained the actuator issues detailed here. He listened. We had the vehicle on a lift and I showed him that in 2 wheel drive the front drive shaft was still turning the wheels and engaging something, and that it probably shouldn't do that when it's in 2 wheel drive. He said he was not totally aware of exactly how the bronco drivetrain works or is supposed to work, but that he was going to call Ford, talk to other technicians, do some research, and get back to me. He wants to make sure they figure out exactly what the problem is, what caused it, etc before they can get Ford to ok warranty work. So I just have to wait now, but at least I've finally made some progress with the dealership. I believe they will arrive at the proper conclusion that it's the actuator. If not, I'll go back and ask the technician to disconnect the actuator and see if that changes things. I'd still love to know what that actually does, though- does it default to disconnecting things or does it default to connecting things?

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[Bmadda]

Update: my dealer had their tech drive my bronco 3 different times before they did what I said they needed to try, which was to shift from 2 to 4H and back. Even if it isn't making noise in 2, shifting to 4H and back causes the noise and vibration every single time. The tech said he thought it could be a number of things. He said it could be the leveling kit that's throwing things off. I explained the actuator issues detailed here. He listened. We had the vehicle on a lift and I showed him that in 2 wheel drive the front drive shaft was still turning the wheels and engaging something, and that it probably shouldn't do that when it's in 2 wheel drive. He said he was not totally aware of exactly how the bronco drivetrain works or is supposed to work, but that he was going to call Ford, talk to other technicians, do some research, and get back to me. He wants to make sure they figure out exactly what the problem is, what caused it, etc before they can get Ford to ok warranty work. So I just have to wait now, but at least I've finally made some progress with the dealership. I believe they will arrive at the proper conclusion that it's the actuator. If not, I'll go back and ask the technician to disconnect the actuator and see if that changes things. I'd still love to know what that actually does, though- does it default to disconnecting things or does it default to connecting things?

From alldata (excuse copy/paste):


Front Axle Disconnect System Operation

Principles of Operation

NOTE: Front axle disconnect is associated with open type front differential - DANA M190.

The FAD (front axle disconnect) distributes torque across the front axle halfshafts for 4WD operation when requested. It reduces the drag and wear on the differential when disengaged, as only one axle is connected to the differential in this instance. It is controlled by the AWD module.

Torque (when commanded or selected) is provided to the front wheels via the front driveshaft, front drive axle and the FAD (front axle disconnect).

When 4H or 4WD Low (4L) operation is requested, the AWD module actuates the motor to rotate the cam. When the cam rotates, it slides the dog clutch to engage with the input shaft from the differential. This action connects the front RH half shaft to the front axle, providing 4WD operation.

 

[Calm horse]

Has anyone had any luck with this yet....mine started intermittently around 4000 miles ...now I'm at 10k...its not all the time and it's mostly at highway speeds 60mph to 80.....22 2.7 sas....would love to give the dealer a little head start b4 they give me the runaround

 

[JasonK]

I also have a vibration felt in 2WD, felt on drivers floor board and pedals, when driving 30mph to highway speeds. More noticeable during faster speeds. 3 seconds or so vibration or hum, then 3 seconds normal smooth driving. Taking into the dealer tomorrow. Hope it’s figured out. Very frustrating.

 

[JasonK]

Ford dealer looked at and drove my Bronco 5 miles. Said my tires are probably too big, but they didn’t notice anything abnormal with the drive. Beyond upset. How many times and dealers do I need to take it to? By the way, I have 35 Mickey Thompson Baja Boss tires, what a joke this ford dealer is.

 

[Ford Motor Company]

I also have a vibration felt in 2WD, felt on drivers floor board and pedals, when driving 30mph to highway speeds. More noticeable during faster speeds. 3 seconds or so vibration or hum, then 3 seconds normal smooth driving. Taking into the dealer tomorrow. Hope it’s figured out. Very frustrating.

Hi there! If you would like additional assistance, please send over a DM with your VIN and Ford dealer info.

 

[Milmand]

I’ve been having the exact same vibration/grinding noise explained here. I have 2022 obx nonsas 4 door automatic. The noise began in September ‘23 randomly on a 8hr road trip where it happened 3 times lasting no more than 10 minutes at a time. After that trip it would happen pretty infrequently in the beginning maybe once or twice for every 10 trips to town (I have a 30min drive at highway speeds to town). I took it to ford and they said they couldn’t replicate the sound so to come back if it got more frequent or I figured out how to replicate it.
I started to notice it happened like clockwork after about 6-7 min of driving at 80-100km/hr the first drive of the day or after sitting for a couple hours every day. It would last about 10 minutes, sometimes more and eventually dissipate. If I slowed down to less than 20km/hr or stopped the noise would go away. After some bad snow days I finally had the opportunity to drive in 4h and found the noise would not happen. Then I saw this forum and tried switching to 4h and back to 2h and found it would always make the noise happen. Perfect. Took it back to ford, told them all I knew. They decided to replace the front axle assembly, test drove it and found the noise still present. So they decided to replace the front diff (found fine metal particles in the fluid and claimed it was a bad bearing) I took it home and had no noise for a couple days and then it got cold again (was above 0 and dropped to -30) the noise was as bad as ever.
Needless to say it’s going back to ford tomorrow. Really hoping they can figure it out this go around. If anyone else has had any success resolving the issue I’d love to hear it.
I find it weird the temperature seemingly has an effect on it, the warmer it is the less severe and frequent the noise, the colder it is the more severe and frequent it is.
id also like to add that driving in 2h after the noise has occurred and dissipated still feels kinda rough, like there’s a resistance and still a faint oscillating sound/vibration

 

[Engine21]

I’ve been having the exact same vibration/grinding noise explained here. I have 2022 obx nonsas 4 door automatic. The noise began in September ‘23 randomly on a 8hr road trip where it happened 3 times lasting no more than 10 minutes at a time. After that trip it would happen pretty infrequently in the beginning maybe once or twice for every 10 trips to town (I have a 30min drive at highway speeds to town). I took it to ford and they said they couldn’t replicate the sound so to come back if it got more frequent or I figured out how to replicate it.
I started to notice it happened like clockwork after about 6-7 min of driving at 80-100km/hr the first drive of the day or after sitting for a couple hours every day. It would last about 10 minutes, sometimes more and eventually dissipate. If I slowed down to less than 20km/hr or stopped the noise would go away. After some bad snow days I finally had the opportunity to drive in 4h and found the noise would not happen. Then I saw this forum and tried switching to 4h and back to 2h and found it would always make the noise happen. Perfect. Took it back to ford, told them all I knew. They decided to replace the front axle assembly, test drove it and found the noise still present. So they decided to replace the front diff (found fine metal particles in the fluid and claimed it was a bad bearing) I took it home and had no noise for a couple days and then it got cold again (was above 0 and dropped to -30) the noise was as bad as ever.
Needless to say it’s going back to ford tomorrow. Really hoping they can figure it out this go around. If anyone else has had any success resolving the issue I’d love to hear it.
I find it weird the temperature seemingly has an effect on it, the warmer it is the less severe and frequent the noise, the colder it is the more severe and frequent it is.
id also like to add that driving in 2h after the noise has occurred and dissipated still feels kinda rough, like there’s a resistance and still a faint oscillating sound/vibration

Hey Milmand thanks for posting this! My 2021 Big Bend Bronco is doing the same thing. I took mine to Ford and they said they heard the noise but couldn't figure out where it was coming from. I have a professionally installed 4 wheel parts 2.5" lift and 35" tires. They said they feel that the suspension upgrade is causing the problem and possibly putting something in a bind. I feel like this isn't the case but more that they didn't want to deal with the issue since it's still under warranty and couldn't figure it out. The issue seems worse for me as well when it's colder outside. Sometimes I don't even notice it when it's warmer weather. If you figure out the issue could you please let me know cause it's driving me nuts. Thanks alot! Also I threw my smaller factory tires back on to see if the issue was still there and it was. I think my next plan for now is to send it to another Ford service center and see what they say...

 

[Engine21]

I figured I’d post a video where I was finally able to catch the humming noise. If you have good ear buds you can hear it quite well.

That is the exact same thing mine is doing! Ford has to fix this problem!

 

[andersman02]

I had this and posted earlier in the thread but.....


I ended up trading up to a Sas.... BUT to ANYONE hearing this problem, the EXACT noise and vibration Runningjerk had, I'm almost certain it's the FAD on the 190 front axels.

My next step to diag was to basically disconnect the FAD (front axel disconnect) (I believe theres a harness connected to to the FAD) and see if it continues or stops. If it stops you know the FAD is the culprit.

the FAD disconnects the front right tire from the differential when in 2wd. If it's not disconnecting completely that could be the issue. the SaS and m210 does not have this FAD, only the m190.

I highly highly suggest people run there own diagnostics (theres a TON of info on this type of vibration in this thread and/ bronco6g) until you can either pinpoint this issue, or at minimum be able to replicate it on the spot every time. Otherwise 9/10 times the dealer will not be able to help.

Happy wrenching!

 

[andersman02]

Ford dealer looked at and drove my Bronco 5 miles. Said my tires are probably too big, but they didn’t notice anything abnormal with the drive. Beyond upset. How many times and dealers do I need to take it to? By the way, I have 35 Mickey Thompson Baja Boss tires, what a joke this ford dealer is.

You need to get more specific with the dealer and give him some help. Vibration to one person, may not be vibration to everyone. As you've driven the vehicle every day, your much much more intune to how it feels then anyone else. Here's how i'd look at it

Try to pin point it. Find a way to make it happen every time you do something.
Does it happen in 2wd only? 4wd? Something in the driveline most likely.
Does switching from 4wd to 2wd cause it? (This was my case an almost certain it was the FAD)
Certain Speed?
Does running over a bump cause it? Front end steering related possibly
Does the sound change if you change speeds? (rotational)- I'd be looking for soming tire related

Vibration like this is incredible hard to diagnose for someone who doesn't daily the vehicle, especially if they can't replicate it on the spot.

 

[pillar406]

Just wondering if anyone else has come across this issue with their Bronco, or if any technicians on here have heard of this.

Dealership has been trying to find the cause of this vibration, noise started out of nowhere while driving at highway speeds, it starts out at a pulsing vibration, almost like a loose wheel, then slows as you continue to drive to about one second on and off. The vibration stops immediately when you engage 4H and comes back when switching back to 2H, warranty covered replacing the entire transfer case but that didn't solve the issue.

2022 2 Door Outer Banks, 2.3L, Auto, Non-Sasquatch, no locking differentials

well if you had the 3.0L I would say its the IWE's not disengaging properly. I don't believe the 2.3's have IWE's but I could be wrong. If you send me your VIN I'll pull it up and see what I can find

 

[JasonK]

You need to get more specific with the dealer and give him some help. Vibration to one person, may not be vibration to everyone. As you've driven the vehicle every day, your much much more intune to how it feels then anyone else. Here's how i'd look at it

Try to pin point it. Find a way to make it happen every time you do something.
Does it happen in 2wd only? 4wd? Something in the driveline most likely.
Does switching from 4wd to 2wd cause it? (This was my case an almost certain it was the FAD)
Certain Speed?
Does running over a bump cause it? Front end steering related possibly
Does the sound change if you change speeds? (rotational)- I'd be looking for soming tire related

Vibration like this is incredible hard to diagnose for someone who doesn't daily the vehicle, especially if they can't replicate it on the spot.

 

[JasonK]

I did paint a whole picture of my issue with the dealer. Just because I didn’t put our whole dialogue here, doesn’t mean I told them it was just a vibration.

 

[Engine21]

I had this and posted earlier in the thread but.....


I ended up trading up to a Sas.... BUT to ANYONE hearing this problem, the EXACT noise and vibration Runningjerk had, I'm almost certain it's the FAD on the 190 front axels.

My next step to diag was to basically disconnect the FAD (front axel disconnect) (I believe theres a harness connected to to the FAD) and see if it continues or stops. If it stops you know the FAD is the culprit.

the FAD disconnects the front right tire from the differential when in 2wd. If it's not disconnecting completely that could be the issue. the SaS and m210 does not have this FAD, only the m190.

I highly highly suggest people run there own diagnostics (theres a TON of info on this type of vibration in this thread and/ bronco6g) until you can either pinpoint this issue, or at minimum be able to replicate it on the spot every time. Otherwise 9/10 times the dealer will not be able to help.

Happy wrenching!

Thanks for the tip! I have an appointment to take it to another Ford service center Tuesday they seem to be aware of the problem. I'll let you know what they end up saying.

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