Intermittent Noise from Rear End

[RPGR90s]

I have a 2019 Edge ST AWD with 86k. Original owner.

 

I am starting to notice an unusual noise from the right rear (as best as I can estimate) when making right hand turns from a dead stop.

 

It's very subtle but noticeable, like a loose shock or something. I replaced both rear shocks with Bilstein's but the problem was happening before the shock replacement. And it only happens when starting off in a right hand turn. Like at an intersection where you stop and then turn right.

 

I'm just trying to figure out what it might be so I can tackle it before it's a huge issue.

 

Thanks so much.

[fastback89]

I have 2020 ST that was making bump noise when accelerating from a dead stop when turning. I fixed it by changing the fluid in the rear differential. I will warn you that the fluid is somewhat expensive but it only required 1 quart.

[Haz]

Good luck!

 

[Samurai Edge]

I had the same issue with my 2020 Edge ST with only 20K miles.  There is a TSB that covers this.  A PDM update resolves the issue.

 

However, if the RDU fluid has never been changed, or if the wrong fluid was used, then the RDU fluid should be changed soonest.

[jaydubau]

This is my typical luck throughout life. 😁

 

Others on this thread had their noises cured by merely changing the diff fluid.

 

But me and my wife's 2020 Edge Titanium with only 40k miles? 

 

We heard the noise and took it to our dealer and had them change the diff fluid. Couple hundred dollars tops. Right?

 

WRONG. They saw metal bits when they were changing the fluid!! Differential is SHOT. Only 40k miles. A $6,000 repair!!!

 

Story of my life.

[Samurai Edge]

Extended Warranty?

 

If the dealership tells you that your car is over 5 years old, and Ford does not warranty Ford cars that old, they are outright lying to you.

 

There a number of reasons that the rear diff broke up.  Here are only two (2):

  - Are you the original owner?

  - Did you ever have the rear diff fluid changed before?

[boostededge]

This thread makes me want to go change my RDU fluid again just for the heck of it 😅

[jaydubau]

On 4/12/2026 at 11:13 AM, Samurai Edge said:

Extended Warranty?

 

If the dealership tells you that your car is over 5 years old, and Ford does not warranty Ford cars that old, they are outright lying to you.

 

There a number of reasons that the rear diff broke up.  Here are only two (2):

  - Are you the original owner?

  - Did you ever have the rear diff fluid changed before?

 

No, I hadn't changed the fluid.

 

Heard back from Ford and they AGREED to pay about $4,500 of the $6,000 bill. 

 

I can live with that. Thank you Ford!!

[Samurai Edge]

I could live with that as well.  You may have a $100 deductible that goes with that but still acceptable.

 

Could be that the fluid was never changed, hence a solid reason for the failure.

The RDU fluid is only a 75W straight fluid so it's not the typical 75W90 or 75W140 found in earlier models.  Plan to replace that RDU fluid every 20K miles so you never have a repeat of this issue