Rear Suspension noise

[SteveO2019]

Greetngs all, I have a 2019 ST, app 70,000 miles. This is my 3rd Edge, first 2 were Titaniums and both were totaled by idiot drivers. This one is by far the favorite, started making a odd knocking sound in rifght rear only when taking off and in right turn, does not do it id left turn. Anyone else experience this? Guess it will go to shop next week.

[Samurai Edge]

Sounds like something loose in the suspension.  Could have a loose / failed rear shock, which would make it simple to fix.

 

Have you looked around the area to see if you can see anything out of place; ie: loose inner fender well, shock not properly bolted in place, etc.

You can only see so much with the wheel / tire installed.

[enigma-2]

This is a highly documented pattern failure on 2019+ Ford AWD. It's probably a failing Active Torque Coupling Unit on the Rear Differential.

 

Starting with the 2919 edges, Ford changed the AWD disconnect system that frequently suffers from internal clutch pack chatter or mechanical failure.

 

When you take off or turn right  the vehicle weight transfers  and forces the rear differential to send torque to the left rear wheel while slipping the inner right wheel, which triggers a distinct clunking, knocking, or thumping sound from that rear area.

 

No recalls on the coupler, but a recall on the rdu. 

21S02 (Rear Drive Unit Lubricant Level.) Applies to certain Edges regarding a low lubricant fill level in the rear drive unit. If the fluid was below the minimum level, the axle was supposed to be replaced free of charge. You should check if your specific VIN was ever flagged for this, as running low on fluid from the factory causes the exact premature failure and clunking you are experiencing.

 

There's TSB 21-2389 for Rear Actuator Noise.

 

Check for recalls by getting your VIN and go to the NHTSA Recall Lookup Tool.

https://share.google/NTvPbYbGnMtqpp5ND

 

(Good reason to have an extended warranty.)

 

 

[garycrist]

I've wondered about running 75-140 with some friction modifiers. (like in a 8.8 LSD)

It should quiet down the chatter some by making the fluid slippier.

 

In looking at the failures so far. One thing is the bearing failures due to overworked thin fluids.

Then as you stated above clutch failure. All of this for fuel economy?

[Samurai Edge]

In which vehicle?  The 2022 is not designed to use that weight gear oil

[enigma-2]

Found this on YouTube. 

 

[Samurai Edge]

That's an excellent video.  And the whole process only takes 16 minutes!  😃

[bruker]

I have a 2020 Edge and it's starting to make the rumbling sound when making a slow right turn. I crawled under and noticed the front of the rear diff is a little damp with oil. Is that also indicative that the Active Torque Coupling Unit is starting to fail? The video above is for I think he said a 2013 is the process the same for the 2020? Thanks for any help.  

[Samurai Edge]

Did you have the software update that resolves issues with the rear diff making rumble noises?   I had some of that on left & right turns, randomly, and that solved that issue.

 

Can you see where the leak is coming from?

  - Is it from the connection to the rear diff?

  - Is it coming from on top of the rear diff?  There is typically a breather hole on top of the rear diff to allow for expansion of air in the rear diff as the oil heats up and expands.  Remember the rear diff is not completely full.

  - Did you drive through something that makes it look like the rear diff is leaking?

 

The above procedure does work on a 2020 but I suggest you make sure where the leak is actually coming from before you tear into this project.

[bruker]

Here's a pic I just took from the driver's side. The area circled is where there's a light coating of fluid. 

 

[Samurai Edge]

Honestly, that could be almost anything.  Car undersides pick up all kinds of dirt & grease from the roadway all the time.

 

Do you park the car in the same place, the same way everytime?

Are there any wet spots on the pavement directly under where the RDU sits?

What happens when you place your finger on that area shown in the picture?

 

All I'm saying is don't jump to conclusions just because you watched that video.

[garycrist]

Are you sure it is not from the drain plug? Clean it off with some Brakleen and monitor.

[bruker]

Yep, park in the same place every night. No spots or drips on the floor. When I wipe it with my finger it's wet but doesn't really have much of a smell. The drain and fill plugs are tight and no evidence of leaking.  

[Samurai Edge]

It wouldn't be from the drain plug since that's in a different area of the RDU.

 

If you are not seeing any spots on the floor, I wouldn't be too concerned right now.  I would just keep an eye out for any leaks in the future.

 

Get that software upgrade done and see if that makes the problem go away.