The Guys at Metal Tech did the work. I have more info on a thread here.

I've been experiencing the same thing in my TRD Pro; "clunk" on small bumps, both audible and felt in the floor. When it first presented (or when I first noticed it) at about 100 miles, in addition to being a "clunk", it was immediately followed by a bit of rattle. After being validated by the dealer, they found that the washers on the front strut assemblies were distorted, possibly from being over-torqued during assembly. They replaced the hardware, and this eliminated the bit of rattle that followed the "clunk", and maybe reduced the "clunk" itself, though most certainly did not eliminate it. At this point, wasn't sure if there was still something wrong, or if this was just the noise I can expect from this new model. Fortunately, a buddy of mine owns the exact same rig, so I drove his... Sounded exactly the same. He had never really payed attention to it, but we both heard it in both vehicles... identical.

What's interesting is that the dealer claimed that the noise was eliminated after performing the above work... But I still heard it clearly after picking it up. I am thinking that the vehicle sitting in the warm shop has a lot to do with it being eliminated on their test drives.

It almost seems like the cold is creating less rebound damping (contrary to what you'd expect, fluid dynamics laws would suggest MORE damping and slower rebound in the cold), and the shock rebound is too quick.. or something.

In any case, it's certainly disappointing; this isn't supposed to be a HMMWV; Toyota needs to pay attention and correct this issue.

I agree that Toyota needs to fix this issue as well. I have stopped any further mods until this is resolved. It seems that the dealer visits are met with partial improvements but no fix yet. I am starting to agree with engineer that we may have to find it. One main reason I chose the TRDP was for a more robust suspension with more wheel travel for both on and off road. I am finding myself avoiding bumps just not to hear and feel the clunk. Once I have my windshield replaced due to a crack across most of it, I am planning to take it in for this issue and I will post the resolution and dealer notes. Also very disappointed.

Same story with me. My pro does it, and a buddy of mine bought a pro shortly after me that does the same thing. He didn't notice it either until I pointed it out.

I noticed it on mine from when I first picked it up in October, and I don't think it was all that cold then so I'm not sure if temp has a whole lot to do with it.

It doesn't bother me that much, and it doesn't seem to affect the handling or performance of the suspension. I am curious about what is causing it though.

I had a 2004 SR5 that had the similar "clunk" and took it in to the dealer back then too. No one found anything then but they showed me the bit of play in the front axle CV boots on both driver and passenger side. I ended up putting 180K on that 4Runner and the clunk was always the same and I just assumed it was some sort of normal anomaly that never showed up as any kind of damage.

Onto this 2015 TRD Pro and the same is happening only a bit more noticeable (probably because I paid way more for this one than the SR5 lol).

Something I have observed is that I can grab the sway bar end links on either side (driver and passenger) and can twist them by hand with a bit of resistance fast enough to hear a metal to metal click as the ball joints reach the end of their range. Is this normal for other TRD Pro's out there?

I ask because I did replace the sway bar links on my 2004 SR5 myself around the 178K mile mark. the ball joints on the old ones when I took them off would wobble freely. The replacement ones that I picked up at a Napa Parts store were much more rigid and took the force of both hands to twist the ball joints free and then it would move but slowly and with obvious resistance.

Could these sway bar links be failing or loosening up so quick that with straight on bumps where both driver and passenger spindles pull up at the same time on the sway bar end links causing the "clunk"?

I also read an older Tacoma forum where a check of the power-steering rack bolts that support it to the frame and the guide bolt for the rack itself were tightened to eliminate the play in the steering rack. I don't feel it in the steering wheel but maybe it's so well isolated these days that it doesn't come through?

I hope to get to troubleshoot these a little further when I get a chance but wanted to throw it out there in case someone else had a chance to validate. Sadly I don't have enough time to leave it with the dealer and from reading these forums it looks like the dealer is not much help either.

Toyota should offer a competition like they do for young future engineers or scientists to solve a problem and give whoever finds the definitive solution some form of reward.

I believe I may have found the cause of the clunk on my rig. It may be somewhat specific to Icon installs on 14+ though, may not apply to the pro. And it would explain why I think I remember it happened when I got the lift installed as well.

I had my driver side wheel off to weld up a crack on the inner fender well and took a good look at everything under there. When I hit the sway bar with my hand I could hear a slight metal on metal clack. Looking at the sway bar as it passes under the body, between the sway bar mounts, I see this:



The Sway bar is hitting a forward mount to the radiator cross bar. Here is a close-up:



You can see it's scraping and even flattening the support bar some. Weirdly this is only on the driver side, here is what the passenger side looks like:



So the bend in the sway bar is asymmetrical with the bend WAY over on the driver side...

Now the cause of this in my case is the icon sway bar relocation bracket. It moves the bar down about 1/2 inch and forward about 3/4 inch. Basically pressing it right up against the forward crossbar mount on the driver side.

Good news is it's fixable in this case. Bad news is not easily :/ I'll have to fab up some custom brackets that don't move it forward so much. Or possibly some longer links might move the bend up high enough to not hit.

A project for another day I fear... but at least I feel comfortable that I found an extremely likely explanation for the clunking in my case.

As far as the TRD Pro goes, did they actually install a sway bar bracket relocate? That is really only needed if a 2.5+ inch lift is installed or larger coils as at full droop the bar will hit the coils in the stock location.

So will this issue still exist if the TRD PRO Suspension is installed on a 2015 SR5?

Since they are only lifting .75 inches in the front there is no real need to relocate the sway bar I wouldn't think. But... maybe?

Someone needs to look and see if there is a spacer between the bushing mount and the frame or not. If not, then I doubt the sway bar is contacting the mount as shown in those pics and it may be something else...

T4Duran, any luck with the Go-Pro experiment yet?

I picked up my TRD Pro yesterday (1st toyota) and took this thread with me in an attemp to reproduce before starting the paperwork. It was about 37F here in Atlanta. I drove 10-20 MPH over speed bumps (turning and straight), straight and turns through stop lights/signs and we could not reproduce it. No clunking (metal on metal nor thud), nor any releasing sounds (such as item under stress/pressure then releasing.) I can try specific actions if someone can provide some guidance/assistance.

That was a good idea and glad it worked to solve your issue Warthog!

but it looks like it doesn't specifically apply in the TRDP as delivered from dealer. There appears to be considerable clearance from the sway bar hitting the posts supporting the bottom of the radiator support crossbeam. Also there is not a sway bar relocate, on mine at least. These photos are from the driver side but having compared with the passenger side it was the same.

Still a work in progress here but all thoughts and ideas will help with the ultimate discovery!

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I just sold that very suspension off of my FJ used a different shock though, man made one heck of a difference.

I hope it stays that way for you. Mine didn't show up until about 800 miles in. I picked mine up in about 50 degree weather. Now when it hits the teens and almost 2000K miles run, its clanking away.

Anyone have any updates on troubleshooting the clunk? Mine is as loud as ever but I haven't had a chance to drop it off again at the dealer.

Mine is at the dealer now. Will post the results once I get it back.