Does your AWD Mav clunk in the rear when slowing down (braking) at around the 13 mph mark?

[ListedGuru]

Hybrids don’t have gears

I was just going to post about the hybrids not having gears. So we have both AWD EB's and AWD Hybrids making the clunk noise so I think we can rule of a transmission issue as Hybrids don't have a transmission. That would lead me to believe it has something to do with the RDU and or AWD system. It does seem strange that not everyone has the clunk noise but those that do it seems to manifest itself at that cursed speed of 13 mph, lol.

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[ListedGuru]

I'm in the Bronco Sport forum as well, it's been reported a clunky sound while breaking in reverse, new aftermarket pads looks like the solution and
It's been reported a clunky sound a low speed, RDU, change the RDU fluid seems the solution
#IDK

What Bronco Sport forum are you talking about? I'm seeing a few different forums. Any chance you have a link to those discussions regarding a clunking sound?

 

[710-oil-614]

What Bronco Sport forum are you talking about? I'm seeing a few different forums. Any chance you have a link to those discussions regarding a clunking sound?

I changed my RDU fluid at 4k miles and clunking sound remains consistent.

My guess would be the mechanical driveshaft disengaging and my guess is many more less perceptive owners also have the same thump.

 

[Backin15]

Ah...didn't know that!

 

[ListedGuru]

I changed my RDU fluid at 4k miles and clunking sound remains consistent.

My guess would be the mechanical driveshaft disengaging and my guess is many more less perceptive owners also have the same thump.

Well that's a good datapoint in that your changing the RDU fluid at 4k did nothing for the clunking noise. I agree that many more owners probably have the clunk they just don't hear it. Maybe as more read about it and pay closer attention they'll notice it as well.

You might be right about this clunk being the mechanical driveshaft disengaging with the noise coming in consistently around the 13 mph mark. I think that 13 mph has to to be where some sort of event is programmed to take place (ie the driveshaft disengaging) like you mentioned. But I still don't feel the sound should be there and whatever is taking place multiplied by thousands and thousands of times sounds like a recipe for something to break at some point. I guess the alternative is to turn of traction control every time so we don't have to listen to the clunk

 

[710-oil-614]

Well that's a good datapoint in that your changing the RDU fluid at 4k did nothing for the clunking noise. I agree that many more owners probably have the clunk they just don't hear it. Maybe as more read about it and pay closer attention they'll notice it as well.

You might be right about this clunk being the mechanical driveshaft disengaging with the noise coming in consistently around the 13 mph mark. I think that 13 mph has to to be where some sort of event is programmed to take place (ie the driveshaft disengaging) like you mentioned. But I still don't feel the sound should be there and whatever is taking place multiplied by thousands and thousands of times sounds like a recipe for something to break at some point. I guess the alternative is to turn of traction control every time so we don't have to listen to the clunk

I'm just not that concerned about it. I've got 60k miles of warranty to replace anything that is not functioning properly.

 

[Mox4615]

Mine does it everytime but the intensity of it is pretty sporadic. Sometimes it’s fairly harsh sometimes I don’t notice. Slowing down gradually seems to make it seem more intense as apposed to somebody who waits till the last minute to apply brakes. I’m not one of those so I obviously noticed it fairly early on with my Mav

 

[808Goose!]

No clunk sound ... yet. I'm only at 1400 mi.

 

[Cancunbadlands]

What Bronco Sport forum are you talking about? I'm seeing a few different forums. Any chance you have a link to those discussions regarding a clunking sound?

https://www.broncosportforum.com/

 

[Phimosis]

I changed my RDU fluid at 4k miles and clunking sound remains consistent.

My guess would be the mechanical driveshaft disengaging and my guess is many more less perceptive owners also have the same thump.

My guess would be the mechanical driveshaft EGAGING.

We are talking about braking and slowing down, right? At freeway speeds, the rear driveshaft and differential carrier are disconnected and come to a complete stop, to save gas.

As your car comes to a complete stop, the rear driveshaft is engaged to give better traction when you take off. Then it disengages as you start going faster, say 15 mph under light throttle, but not until something like 40 mph if you’re using full throttle.

So the big question is, “is the Maverick programmed to always have the RDU clutch engaged under 13 mph?”

If so, any slop in the rear driveshaft u-joint or in the differential carrier gears could cause a clunk when power is applied to them to spin the drive shaft up from a dead stop to 602 rpm (calculated on OEM tire with 729 revs per mile, 3.81 gears, 13 mph).

And nope, my 2024 AWD Maverick doesn’t do this. But it only has 6k miles on it.

 

[710-oil-614]

My guess would be the mechanical driveshaft EGAGING.

We are talking about braking and slowing down, right? At freeway speeds, the rear driveshaft and differential carrier are disconnected and come to a complete stop, to save gas.

As your car comes to a complete stop, the rear driveshaft is engaged to give better traction when you take off. Then it disengages as you start going faster, say 15 mph under light throttle, but not until something like 40 mph if you’re using full throttle.

So the big question is, “is the Maverick programmed to always have the RDU clutch engaged under 13 mph?”

If so, any slop in the rear driveshaft u-joint or in the differential carrier gears could cause a clunk when power is applied to them to spin the drive shaft up from a dead stop to 602 rpm (calculated on OEM tire with 729 revs per mile, 3.81 gears, 13 mph).

And nope, my 2024 AWD Maverick doesn’t do this. But it only has 6k miles on it.

I follow what you're saying but I don't think the engagement is nearly that linear.

NOW - the Maverick AWD system is NOT the same as 4A (AdvanceTrac in a Bronco) but my Bronco in 4A would engage at some really random times and was not engaged as I came to a stop.

Unfortunately because they removed the power split screen for 2025s we have no visual indicator of what is happening with AWD.

 

[iceman33]

When a slow down and hit 20km/h i can feel the rear end engaging. It feel like loose stuff hitting gently the back of the tonneau but its empty.

 

[BLUEOVALRACER]

I haven’t noticed any clunking with my ‘25

X2 and Mine is also AWD.

 

[Darryl]

Well if my poll is an accurate indicator it seems as though the AWD rear clunk issue is the exception and not the rule. I see (2) yes votes and one of those Yes votes is me.

We've seen a few that make some strange noise or vibration during low speed turning maneuvers. The fix ranges from changing the fluid to replacement of the rear differential. The rear differential is covered under the 5/60 powertrain warranty if I'm not mistaken.

 

[BLUEOVALRACER]

I paid close attention this morning in normal and Eco. Hard on brakes and easy on brakes no clunking.

I did the same Yesterday after reading this Thread and like I said above I didn't feel or hear any clunking at and around that speed.

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