Undiagnosable Clunking

It just sounds like the typical interior rattle on stock suspension over bumpy terrain. I had a Subaru on a 2.5” spacer lift and it rattled like that.

 

When you're in the vehicle it is apparent that the clunk is from outside the cab. But I have emptied the glovebox and center console without luck

 

I wish I wouldn’t have opened this thread. It’s going to drive me nuts. I’m going to have to thoroughly search through my truck to see what could possible rattle like that.

 

Rear seats have been deleted since the clunking and front seat is secure. I know because I had to loosen it for unrelated reasons.

 

Haha that's how I've felt for months. Im a stress case when I drive this thing on the weekends

 

By no means do I have a clue, but if it isn't the bumpers , the only other thing different is the gears. Can that have an adverse affect on something, like binding or out of sync in the transfer case?

 

Top mounts on coils a re e tight, right...simple thing but can cause this clunking sound on the strangest circumstances...

 

If you’re confident you tried and checked everything, might be worth trying a set up like this where you install probes around the chassis and try to pinpoint the sounds.

$101 Steelman ChassisEAR Automotive Diagnostics Multichannel Electronic Stethoscope Tool, 6 Noise-Finder Microphone Clamps with Leads, Over-Ear Headphones

https://www.amazon.com/dp/B000IHIAES/ref=cm_sw_r_cp_awdb_imm_MX25YV04WV519J3QKC08

 

You said the engine doesn’t move much when revved but have you put more of a load on it? GENTLY Power braking from drive to reverse listening for a single thump and looking for excessive movement... really sounds like a mount to me. Could check this very quickly in the driveway.

 

It's been in jacks a few times and I've checked wheel bearings and drivetrain rotation. Everything is smooth

 

Yeah that's been checked as well

 

I revved it in drive while on the brakes but other than that no load. Coukd you elaborate on this power braking from drive to reverse method?

 

Just wanted to say that this is probably the most descriptive thread I've ever read across any forum regarding hunting for a sound. Well done on actually describing everything.

With that being said, I have nothing helpful to offer that hasn't already been suggested; I do have a similar (almost identical) sound on my 4Runner that I have tracked down to a skid plate bolt coming loose, but you've already answered that. This feels like me trying to track down a front end clunk the 4Runner has that I can feel/hear but only when driving in the rain and is based on longitudinal weight transfer not bumps or turning (also been checked over numerous times, well upwards of $1k in parts thrown at it, etc)

Good luck tracking this down, I feel for you

 

Check your hood stops?

 

Haha thanks. I feel your pain!

 

Yes sir. I actually had an epiphany about the hood while driving a while back and was super excited to pull over and check it but that wasn't it

 

So far the two new things I'll be doing are replacing radiator bushings just for the hell of it and attempting to hoist the engine up to check engine mounts more thoroughly.

 

With your foot on the brake put it in drive and blip the throttle. Without much hesitation shift to reverse and touch the throttle. Repeat several time to try to create a clunk. The torque goes from pushing hard one way to pushing hard the other way when timed correctly. Working in collision repair I have found several broken mounts over the years doing this. Some more obvious than others. Can really help to do it on a lift with eyes underneath in case it’s a rear engine or tranny mount.

 

How solid is the remote res mount? Any flex on either side or contact with anything?

 

Obvious outside right? Have someone do that driving and sit in the bed of your truck. Did you check that your muffler and any shields are secure after the regear?

 

If you are 100% firm on your statements that it started immediately after regear and bumper install and that removing the bumper doesn't solve it then by logic it can ONLY be related to the regear. One bracket in particular on the drivers side is odd with 3 different bolt/nuts holding it on that doesn't seem like proper thread engagement to me so that fuster cluck is suspect.



If you aren't 100% firm on the above statement, I'd triple check the motor mounts and all the shock and suspension bushings - every worn suspension part that I've ever found wasn't able to be detected just shaking it by hand, some required jacking up on frame then up on LCA to cycle suspension, or having someone else drive and stomp brakes to load the suspension and floor it to lift the suspension, OR prying with large pry bars to see the play in some components not very easily.

Is there any feedback in the steering wheel coinciding with the noise? Did the sound start immediately after the steering rack bushing replacement (when were those done in relation to the regear)? Those bushing sleeves and end plates are difficult to align on top of the rack when tightening the bolts blindly.

 

Not to thread jack but I’m also experiencing a clunk in my front end. Strange that the last mod I’ve done was also re-gear to nitro 488. I noticed it a couple weeks ago after driving a pretty bad road full of pot holes and a lot of bumps for a couple hours to get to a dirt biking area. I’ve checked and re-torqued all suspension bolts/cam bolts and front diff/axles/wheel wearings where also checked, found nothing loose or out of spec. I haven’t checked motor mounts yet, think that’s the issue? It only clunks on square edged bumps, rolling off/up curbs, pot holes, and speed bumps, I can also feel it in the floor and steering wheel. Here’s a video https://youtu.be/KgqhYsonWfs

 

Just did all of this and wasn't able to create a clunk or any unusual sounds. But I'll still look into the motor mounts a little more

 

Bolted to the frame with 10 mm threads. I could probably hang off them

 

Very obvious, I turn heads of people very far away coming down the trail.

Yeah I've checked all that stuff, all secure

 

Those bolts/bracket has been checked.

I'll take another look at the motor mounts, most of the suspension components are new with the exception of the shocks which are a year old, but they've been looked over multiple times now. I'll probably swap them out entirely if the motor mounts aren't the fault.

No noticeable correlation between the clunk and steering wheel movement or position. It happen when driving perfectly straight as well, just slightly less often. I've had two alignments done since then and the rack bushings were replaced well before the the clunk started.

 

I may be WAY off but a simple test can confirm this for you.

See this post (specifically post #72 for the location). Have someone bump that harness with their fist while you are in the cab. See if that is the sound you are hearing. If that is it, secure the harness. I went through similar checks for months trying to locate my issue. Turns out, it was this harness and to me, from your video, sounds like what I was hearing on mine.

https://www.tundras.com/threads/2018-“clunk”-noise.20749/page-3

 

The bracket that this wire loom hangs onto has two nuts on it. I had a similar sound to @SR5camper after I had failed to replace one of the nuts after changing spark plugs. Worth a check to make sure they are tight.

 

My bracket was secure, the harness was loose and had to be zip tied to be more snug against the bracket.

 

Yes, I understood that. I figure OP could look at your post to see the bracket I was referencing for his issue.