Groan From Rear of Car While Driving

[dsevier]

Our 2014 Leaf S (68k miles) often, but not always, has a groan or grunt near the rear, possibly right rear. It happens at lower speed say 0-15 mph or so. It is not a metallic sound but sounds more like rubbing like a dry bushing. Lastly, it seems worse when cold outside. If it continues and I can pinpoint it better, I will look at calipers, pads, rotors and wheel bearings. But is there a likely culprit inherent to the LEAF design/build, might a good place to start. Thanks!

 

[dsevier]

Update, had two people in the rear seat and they said sound was on left side rear and occurred when braking for the first few stops at low speed then went away...

 

[TobyHolland]

Update, had two people in the rear seat and they said sound was on left side rear and occurred when braking for the first few stops at low speed then went away...

I'm almost completely certain that's going to be down to surface corrosion on the brake discs - for some reason, the same corrosion on the front discs is inaudible.
It generally clears on the first or second stop of the day - you can encourage it to clear more quickly by charging to 100% before leaving, or selecting N with the shifter, making the mechanical brakes work that bit harder......

 

[dsevier]

I'm almost completely certain that's going to be down to surface corrosion on the brake discs - for some reason, the same corrosion on the front discs is inaudible.
It generally clears on the first or second stop of the day - you can encourage it to clear more quickly by charging to 100% before leaving, or selecting N with the shifter, making the mechanical brakes work that bit harder......

Toby, Thank you for the explanation. I suppose braking very hard would also use the mechanical braking to help get rid of the corrosion.