Clang sound when decel past 20mph

[oltombon]

2020 TRD ORP w/ ~35k miles.

For the past couple weeks, every time I decelerate past 20mph when stopping, I hear a single, relatively loud clang sound from underneath the vehicle. This happens every time when the terrain is flat or downhill as I decel past 20mph. The noise is always right at the 19-20mph mark. Sometimes it's a couple quick clangs, sometimes a single clang. If I am braking coming up a hill with the nose pitched up, it won't make the sound. It also never happens under acceleration or at any other speed. Only when slowing down, on flat terrain or downhill, as I crest below 20 mph.

I looked around under the vehicle for something loose but all I found was the chain hanging from the spare. I ziptied that to the rim of the spare but the noise persists. Since it's so specific and repeatable, hoping someone else has had this issue and been able to source it?

Here's a video: https://streamable.com/fy2aah

 

[Sonoran_Desert]

Do you get the same sound when coasting down to 20 mph in a gear other than "D"?

 

[oltombon]

Yeah, I just went and tested this. I get the same noise coasting under 20 in neutral too.

 

[FoxtrotRomeo]

Do you feel anything when it makes the sound?
Have you followed the maintenance guide on driveshaft lubrication?

 

[oltombon]

Do you feel anything when it makes the sound?
Have you followed the maintenance guide on driveshaft lubrication?

I don't really feel anything when it makes the sound. It's been serviced regularly at the dealer since I bought it new, but trying to avoid taking it there over this.

 

[Humble Leader]

it sounds like a heatshield rattle. I had a couple loose over the years and they would rattle at strange times, seemingly like yours it's like the combination of the angle of the vehicle, speed and even rpms somehow make it rattle.

have you checked each heat shield and really gave them a pull to see if they are loose. including the heat shield around the cat. they are so flimsy that even the slightly touch against the exhaust or anything to cause vibration makes a sound

 

[Sonoran_Desert]

The something loose makes sense. While coasting and at around 19 mph, the transmission performs an auto shift down to next lower gear and this causes the vehicle to very slightly jolt. That jolt is enough to rattle anything that is loose.

 

[obxbird]

Make sure those zirks are greased...had the same problem until i greased the zirk on the most forward part of the main shaft where it slides. Problem Solved!!

 

[smann]

maybe driveshaft or diff related?

 

[oltombon]

To close the thread, ended up giving up and taking to a local tech. It was the backing plate on the rotor. He said he thought the dealer put the truck down off the lift without tightening the lugs enough and that allowed the backing plate to hit the rim when the car would pitch fwd under braking. He bent the shroud back a bit and the noise is gone.

 

[03_4x4Runner]

To close the thread, ended up giving up and taking to a local tech. It was the backing plate on the rotor. He said he thought the dealer put the truck down off the lift without tightening the lugs enough and that allowed the backing plate to hit the rim when the car would pitch fwd under braking. He bent the shroud back a bit and the noise is gone.

Thanks for the follow up. It may help someone in the future.

 

[Humble Leader]

To close the thread, ended up giving up and taking to a local tech. It was the backing plate on the rotor. He said he thought the dealer put the truck down off the lift without tightening the lugs enough and that allowed the backing plate to hit the rim when the car would pitch fwd under braking. He bent the shroud back a bit and the noise is gone.

yes thanks for closing the thread . It's a pain when you find a thread with the exact same problem as you and there's no resolution!