"Thump" noise in cabin when hitting bumps.

Hey taco enthusiasts!

I've been dealing with a persistent issue that's left myself, some local mechanics, and friends scratching their heads.

I originally posted a thread in the Suspension sub and had a lot of initial help but haven't had any with GoPro update so wanted to try and follow up here as I'm not sure now that the noise is suspension-related.

I'm hearing a clunking noise that seems to originate from the passenger front suspension, possibly around mid-dashboard height. It happens when I hit sharp bumps at speed, drive over washboard roads, or make tight left turns downhill (oddly, not when turning right). Strangely, it doesn't occur during normal driving, swerving on flat roads to induce body roll, or when I shake the vehicle while parked.

I've tried everything from self-diagnosis to consulting two different shops. The first shop thought it might be the sway bar end links, so I replaced them, but no luck. The second suggested my springs might be catching on the upper housing during compression, so I applied silicone, but the noise persists. Both the driver and passenger sides show wear marks, ruling out this as the cause.

No matter how vigorously I shake the vehicle or hit parts with a mallet while stationary, I can't reproduce the sound.

This issue has been ongoing for about three years, and while it hasn't worsened, it's incredibly frustrating.

Specs:
- Vehicle: 2019 TRD OR
- Fox Performance 2.0 Coilovers (installed by the previous owner)
- Wheels: TRD 17" 4runner
- Tires: BFG KO2 265/70 R17

Actions taken so far:
- Confirmed lug nut torque security.
- Consulted with technicians at two local shops who heard the noise while driving and inspected the vehicle on lifts, but the issue persists despite their recommendations and part replacements.
- Ensured skid plate is secure.
- Checked UCA, LCA, wheel hub, and sway bar for play—found none.
- Tested by shaking the truck vigorously and compressing the suspension without reproducing the noise.

Observations:
- No play or looseness in steering; responses are firm.
- Noise originates near the passenger side dashboard or floorboard, with no cabin vibration.
- More noticeable downhill and turning right, even on smooth roads, and on hard impacts to the passenger wheel.
Video analysis:
- Noise is not audible in GoPro videos, though I heard it the entire time while filming from in the cab.
- Minimal visible movement in videos, except for some engine movement in one.
If anyone has insights or similar experiences, I'd greatly appreciate the help!

Videos:
https://youtube.com/shorts/hGLUrmo8aBY?si=25RwYmxYdwcX9-qt
https://youtu.be/Osp-FZWqsA8?si=E-4a3hAMlAyKg57v
https://youtu.be/qV_s3EH_1ps?si=arps8UKTMEd05Q5f
https://youtube.com/shorts/HqVWgQldN5I?si=bBcziQjodPW9SwSm

Photos:
Passenger-

Driver-

 

Front facing passenger video, Does that lower control arm not look like it is moving in and out some? It looks like a sloppy bushing possibly? It is hard to tell because the lighting being under the truck.

 

Maybe not suspension related? Could it be your glovebox door? Or something in your glovebox?

 

Sorry I didn't watch the videos. I'm just not a mechanic. Something about your description of the issue made me think of the thread about body mount bushings https://www.tacomaworld.com/threads/3rd-set-of-front-body-mount-bushings.701993/

Probably unrelated but if you've checked everything with the suspension, maybe it isn't that. Good luck.

 

You know your on to something here. It does look like there is quite a bit of play in that bushing compared to the others.

Anyone have a guess as to why I wouldn't hear the clunking sound in the GoPro videos? I feel like it's so loud in the cab that I would have assumed I would have heard it in the videos even with the road noises.

 

Strut. Had a clunk one time entering dips in the road: Nothing on extension stroke, "clunk" on compression.

 

I had a similiar thing with a set of rest shocks. They lost their nitrogen charge and it was almost like a deadspot you could feel/hear the piston go through. Had a re charge it helped but ultimately had to swap them out to eliminate the proble.

 

This is a interesting idea that I had not considered.
Would there be any way to reliably test to see if these body mount bushings are the cause?

Just thinking out loud here, not saying your wrong:
If the strut were the problem wouldn't I be able to replicate the noise by making the strutt cycle through its compression by vigorously shaving the vehicle while it's stationary? I did this with a few buddy's standing on my sliders and jumping up and down. We were able to make it hit the bump stop but no noise was made in the cab.

 

Generally yes, I was able to find mine by removing the shock. But it was almost impossible to replicate by jumping in the truck. Once the shock was loose I could feel it on a really fast compression.

 

I’m having a similar issue in my 3rd Gen. Installed new suspension and all the sudden I’m getting a clunk on slow speed small bumps in the road. Everything feels tight. Everything has been re torqued about 5 times now over the last few weeks. I’ve heard the front body mount bushings go out super early on in these trucks. Curious if you found a solution yet?

 

FWIW: I have had these same clunks on a few vehicles. They were a bear to pinpoint. On one it was a front strut and on another one it was a rear shock.

 

I think this is because sometimes a person can't really manually generate/replicate the same or equal amount of force that you get with real-life "live" travel, especially with coil-over struts and especially on rebound: unless you force it with a brisk run over a good/tall speed bump.

 

Issue I have had is bad UCA. I have gone through SPC and ARB all lasted about a year.
Looking at the videos your look likentpu can use some grease in the ball joints. I think you have ARB UCA and as an FYI they are on backorder for parts. Good luck with finding the issue.