Rear metallic clank on 2016 LC

[pdosescu]

Car:
2016 LC w/ 135K on the clock. All OEM except the Toyota front strut spacer. OEM tires.

Issue:
I can hear a metallic clanking around 10-15 mph as I let off the throttle (like on a neighborhood street). I can only hear it with windows rolled down, which tells me the two pieces clanking together are not connected to the cabin. There’s no sound inside even with AC and radio off. Been tracking down over the past few days but I first heard it a couple of months ago while walking down the driveway and my wife was pulling up in the car.

Things I’ve tried:
I’ve crawled under and tried to shake various suspension parts. Nothing seems loose

I’ve checked spare tire and it’s tight. The chain does dangle , however and that’s my main suspect at this point.

Zerks last greased 5-6K ago and driveline seems tight.

I’ve jumped up and down while stationary to see if it’s shocks/springs and shook the LC side to side. Seems to happen only while moving. There’s nothing I notice in terms of looseness or stability while driving. It’s as tight as ever.

Could the brake pads be the source? Sticking caliper that has a sudden release…? Could the spare tire chain be swinging around and clanking? Next stop is to get it on the lift and tap with a rubber mallet but I wanted to get some input just in case I’m not the first.

Thanks in advance!

 

[Bighead]

It could be the spare chain. Easy way to rule it out would be to zip tie it.

Spitballing here:
Did you check the spare and make sure it isn’t moving around? I had that happen after a tire rotation at Discount. They didn’t have the bracket on the wheel properly and when it was pulled up it wasn’t centered and moved around enough to make some noise.

Check the skidplates if you have had service done at a dealership. Had an oil change done in the early ownership days and they didn’t attach a couple of points and it was bouncing a bit over bumps just enough to rattle.

Loose exhaust?

 

[nwfl4runner]

Check wheel weights too

 

[doru]

I always keep the spare chain hooked onto itself using some 14awg electrical wire. This way the chain is not blasted by road crap all the time, and it is still easy to get the spare out when needed w/o having to cut anything or using a tool for that wire.
For just a test a ziptie will do.

 

[pdosescu]

Thanks , everyone. I’ve checked the wheels weights and all seem to be on there snug. This is the way my spare tire looks and I think you’re right about trying a zip tie out. I did discover a loose bolt on the front left side skid plate but I swear the noise is coming from the rear … I’ve been tricked by acoustic before tho.. will tighten the bolt and zip tie and see what happens.

 

[pdosescu]

Update:
I keep hearing the sound even after securing the spare tire chain.

I've inspected all wheel weights and they are all stuck on tight.

I now believe it is coming from the rear driver (or possibly passenger) side brakes, 5-15 seconds after the pedal has been released. The sound never happens when the brake pedal is applied.

I've watched several YouTube videos of caliper/caliper pin noises and it sounds very, very similar. My front and rear brakes were replaced at 88,057 miles (roughly 47K miles ago. Toyota history shows pads were replaced and rotors resurfaced). They currently measure 5mm front and rear. I think a proper front and rear brake job (pads and rotors) with everything cleaned and lubricated will clear this up.

This is a link to a nearly exact sound I hear... this one is just forcefully made, where as mine is just 2 -3 times here and there

 

[doru]

The caliper cannot make contact with the torque plate as in the video (unless your caliper is totally busted but you'd have bigger problems than noise).
We have spring clips that hold the pads at each end. Are any of your clips broken or lost tension? It can happen.
The pads should be greased on the back but even w/o that they should not be able to move so much to clunk so loud.
5mm means 36% life left, plenty.
It doesn't matter how many miles you have on the truck since then - driving highways require little braking. Instead of doing a full brake job (throwing parts at the problem) I would focus on the issue at hand. Take the rears apart and inspect the parts, replace what's questionable and put them back properly. Just make sure you mark what pad goes where and put them back in same place.