4th update. Source located. Please help me locate this noise before I go crazy. 1st Gen Tundra.

All those fittings get lubed every year lol. Just done in October 2022.

 

Well, the fact you can hear it even over the lightest bumps like a manhole, that's a clue in and of itself.

To me, it says whatever it is, it's probably just barely loose enough, if it were super loose, it would probably take bigger hits to hear it.

Could it be something external to the truck, like sway bar bushings going out? Have you rolled down the back window with a friend in the back, and have them stick their head out the window to see if it's louder outside than it is inside? Maybe stick a friend in the bed of the truck with a stethoscope on the cab, then on the bed, and see if it's there?

Have you checked with a load in the bed, like three or four friends? You check the rear shock bushings to make sure they're blown out?

 

Thanks again for all of the replies.

After everything I'd tried and looked at nothing has changed.

Speed is 15-20 mph.
The noise is passenger side rear near the rear cab mount. I guess that makes sense because that's where the frame and cab connect.
Can't hear anything up front.

I just took a ride with my friend (260lbs) in the back with the seats folded up. With him back there it is making noise even on a smooth road. Almost all of the time.
With only me in the truck it needs something like a manhole cover.

This extra weight making it so much worse is what's so confusing.

We did notice something. I don't think it's new. Just didn't try it before.
I turned the corner going right while it was making noise. The noise was on the right and it shifted to the left momentarily. Then back to the right.

This is crazy.

 

@gagecalman Just spitballing here. Have you tried rolling the windows down while driving? Maybe its a window regulator that's loose and its tapping on the body panels? I would try all the windows, individually, even the back window and roll them down, back up, roll them halfway. Do the sunroof if you have it.

 

I would be tempted to remove the door panels on that side and see if you can see anything moving. Have your friend watch while you drive.

 

I have no clue about your sound but funny story. My old GMC had a noise every time I went around a corner you would hear what sounded like a ball rolling under the dash somewhere. I looked for it for years. Never could figure out what was causing it. Fast forward to last year I had a water leak. In the process of evaluating where it was coming from I found the rolling ball noise. It was a marble in the rear floor vent under the driver seat. I guess one of my kids put it in there when they were little. I cannot get it out easy so its still there. Hope you find your noise a little quicker than I found mine.

 

Ha! I told a similar story about my previous GMC Sierra. Goddamn clunk at weird times. Hammering the gas. Taking corners. Sometimes a roller sound, sometimes a THUNK! I cleared EVERYTHING out, center console, entire glove box with its contents, all but the driver seat and carpet. It was making me furious.

I was at my wit's end and finally gave up. One day, I broke down and dropped the headliner to refinish it. Pop out the sunglass holder to remove the overhead console ... DAMN MINI FLASHLIGHT. That was the cause the whole damn time. It would roll back and forth stopping/going. It would slide side to side on turns.

Lesson learned: Just because you think you got everything out, you probably didn't get everything out.

Oh, and sometimes bolts will rattle loose and you'll find in weird places. Happened when my wife's previous Highlander driver window started rolling up with a *POP* sound. I posted videos on here in the Lunch Table thread desperate for help. Nada. Well, I finally popped the door panel off, and dragged my hand down in the door bottom, and there I found a bolt for the window channel. Go figure. It made similar noises.

Never know when bolts are gonna back out. Hell, in all honesty, it could be the rod for a rear door lock, rear door handle... I assume you tested the manual function of the lock by locking it, then confirming the door is actually locked, then unlocking? The little plastic clips that hold the rod to the levers are known to break, and this sounds similar to one of those rods tapping on shit.

 

Side steps tight?
No broken leafs?
Front leaf mount tight?
Bed bolts tight?
Parking break cable isolated and routed correctly?
Bad u-joint?

 

Ooooh, I know OP doesn't have a front leaf, but a LOT of people have bitched and complained about the plastic shims between the rear leaf springs wearing out and making the most annoying ass racket known to man.

Again, you should be able to catch that one if you have someone in the bed. And it'd take a really small bump to make the sound happen... AND it would definitely reverb through the frame, and probably into the cab!

 

$100 it’s a 10mm socket. 1/2” drive.

 

Jokes aside I was actually thinking it sounds like something rolling around. A bolt that came lose or something along those lines.

 

Thanks again for the replies and advise.
This truck has about 77K miles.
I think the noise is too loud and focused at that right rear mount to be something in the doors.
I think it getting so more frequent by adding some weight to the back seat is a clue but I don't know what it means.

All items look fine. I will look at the rear springs again. I can apply the brakes and the parking brake and it still makes noise.

I attached some pics. The spare tire was removed and the cable is tight and not making noise.
I will look closer at the springs. I also have a

$163 Hellwig 991 EZ-990 Helper Spring Kit

Hellwig 991 Level Helper Spring Kit hat's been on there for 4 years.

 

May be time to buy new tools!

Chassis System Ears Electronic Stethoscope Diagnostic Kit with Headphones, PLAYOCCAR 6 Channel Car Engine Noise Finder Sound Detector Tester Tool Set

$73 Chassis System Ears Electronic Stethoscope Diagnostic Kit with Headphones, PLAYOCCAR 6 Channel Car Engine Noise Finder Sound Detector Tester Tool Set

https://www.amazon.com/dp/B09CD7NDK3

 

Spray some lube in between your leaf springs

Oh man. I wonder if your truck suffers from what the rest of us low-mile guys do? You ever seen under your valve covers?

Here's some of our fun low-mile samples from different owners on the forum: example 1 / example 2 / example 3

Seems like the most common way to get that low-mile on trucks this old is lots of short-trip driving. And it also seems a lot of owners seem to think you only change oil based on mileage alone, regardless whether it's short trip driving or not.

I'd love to see under your valve covers one day...

 

I do not believe that is a sound coming from the leaf springs.

 

It's most unfortunate you dont live nearby. I'd love to try an tackle this.

Honestly man,
It might be a great idea to take a step back and sit down, brainstorm.

When did the noise start?

What was done just prior to the noise appearing?
Mods, maintenance, pot hole, towing, people in the rear seat, etc

What could have been affected based off the last use, series of uses leading to the noise?

What induces the noise, what reduces the noise?
Makes noise better/worse?
How does the body react to said better/worse?
How does suspension react?
How does driveline react?

Any environmental influences?

Anything else conditional to the noise?

Etc

 

Ah, I don't either, I'm just over here chuckling that something said on a forum could make a dude lube his rear end.

(j/k)

 

Measure the gap on the drivers side body mount and compare to the passenger side. Perhaps the rubber has deteriorated and collapsed.

You could try loosening that corner body mount and see if the noise changes.

 

So I took a break to get some sleep.

No mods.
Noise started about 2 weeks ago.
New tires installed 6 weeks ago.
New muffler installed and hangers replaced (all welded) 8 weeks ago.
No noise or issues after these items.
Truck gets regular maintenance by me.

Today I checked under the entire truck. Looked for anything missing or loose. Looked for that 10mm socket lol. I tapped everything with a hammer. Nothing. Everything tight.
Shook the exhaust. No noise.
I went over the front end even though I don't think it's up there. All good. LBJ's have no play.

Speed is 15-20 mph.

Here's the clue even though I don't know what it means:
With just me driving it needs something like a manhole cover or small bump to make noise and its a lot less frequent.
I have 5-50 pound buckets of stone. I put the 250lbs of stone in the back of the bed and then moved it up to the front of the bed and the noise is the same as If I'm driving by my self.
In other words the weight in the bed doesn't make it worse.
I put the 250lbs of stone in the rear of the cab, on the floor, behind the seats and the noise is happening all the time even on a smooth road. A lot worse.

I have no idea what to do. I'm not even sure where to take it.

Thanks for reading and the great replies!

 

Gonna mention it again because it doesn't seem like you're gonna be able to locate it with any conventional methods. With this kit, you place sensors in six different locations around the steering/suspension/chassis. Drive around with it connected. When the noise happens, a corresponding light will blink on the panel. This will get you in the ballpark area. Then you can place all six near where the first one occurred to narrow down the sound.

Stethoscope Diagnostic Kit

$73 Chassis System Ears Electronic Stethoscope Diagnostic Kit with Headphones, PLAYOCCAR 6 Channel Car Engine Noise Finder Sound Detector Tester Tool Set

https://www.amazon.com/dp/B09CD7NDK3

I mean, it's only $80. And I think you've gone through $80 worth of your time on this already!

 

Last advice I can think of for now.

Jack up each wheel. Slap test, and confirm torque on lugnuts. It's entirely possible one of the studs sheared or something is loose. Consider rotating your tires while you're in there. Yes, I realize it's not normal to slap test rear wheels, but it's worth jacking up and checking it all the same.

 

This description makes me think the cab or mount is the culprit, perhaps the sheet metal of the cab itself. I had a 2002 Pathfinder that I broke the rear unibody in the whoops in Baja back in the day. It sounded like your video. Can you pull the carpet and look for cracks in the metal? Maybe undo the cab mount completely and see if it changes.

 

Passenger door window inside door?? Did you take off the panel to the back window, take off the door panel, take off the plastic pieces and check out the seat belt bracket?? Still thinking it is wind related, all windows down? Hoping you figure it out???? Dang!

 

Thanks for all of the replies and suggestions.

I took a little time to go over all of the info.
Because the noise is at the right rear mount and the extra weight in the cabin makes it worse I could only think it was something with the mount even though it looks fine.

I decided to spray it with some Blaster Industrial Strength Silicone Lubricant Spray. Very nice stuff. As soon as I drove it I felt relieved. The noise is gone.
I didn't spray any of the other mounts.

I have no idea why that mount was causing the knocking noise and why the silicone made it go away.

Any thoughts ?
Should I just spray it from time to time?

 

You’ll know why as soon as you disassemble it.

 

I would consider ordering a new body mount. I don't recall them being extremely expensive.

 

I think he should drive without one for a week, it’ll help toughen him up and get used to weird sounds and jolting bumps.

 

522050C040 $130 list. Probably do both rears?

It's a 2006 Toyota. There shouldn't be any weird sounds and jolting bumps.

 

It's still a 17 year old vehicle. Dash squeaks come to mind. Cold weather pulley squeaks as well.