Undiagnosable Clunking

It all started after I had 5.29 gears and front and rear SS Built bumpers installed last summer. The very next trip I noticed a horrible clunking coming from my front end.


I've personally spent 10+ hours under this truck torquing bolts, placing foam/rubber fuel line on possible contact spots, removing parts (including the front bumper) and test driving, and just generally banging on stuff trying to replicate the clunking without luck. All components in the engine bay are secure and triple checked. Ive taken it to two different shops, one of which is considered the Toyota truck specialist in the Phoenix area and they weren't able to figure it out either on the two occasions it was there.

The sound is slightly more prominent when turning and only occurs on certain sized rythmic bumps. It does not happen when hitting cracks in the road, speed bumps, or even jumps.

You'll notice right off the bat a very loud and annoying clunking/knocking. It occurs a few times throughout the video



Currently have Fox 2.5 DSC coilovers, OEM LCA's, LSK gen 2 UCA,s and stock tie rods. In the persuit of eliminating the clunking I've replaced both the upper and lower control arms without making a difference, other than making my wallet slimmer. Steering rack bushings are energy suspension and pretty new, tie rod end joints have zero slop.


If anyone has any suggestions on things to check or experiences with a similar sound I would really appreciate it. I have had little faith in the truck since this began and I'm worried one day something will break and leave me stranded in the middle of nowhere.

UPDATE: AC condenser bushing have been replaced, passenger side firewall mounted wiring harness has been secured better. No improvement.

 

Great post - describes the problem well and you can clearly hear the clunks. Basically the perfect way to post a topic like this

I had a very similar noise on my old Tacoma and it's worth testing a similar solution. I thought it was the coilovers and even went as far as rebuilding it. Turns out that when it hit certain types of bumps (always the same type on the road down the street!) the small gap between the fender and my ARB front bumper was making contacting. Made a noise very similar to yours.

As a simple test, take a piece of rubber or even rolled up bicycle inner tube and slide it in-between here:



Add it on both sides and add enough that it won't fall out.

I realize my experience was with a Taco and the bumper is different, but the noise was almost identical. It's an easy test.

 

I forgot to include that very important piece of information. I've gone so far as to remove the bumper and grill to test drive and it still clunks

But good idea, it took me a while to think of trying that.

 

Was it Ben that looked it over? I had a broken motor mount and it made noise that could never be found. Have to lift engine, can’t visually see if it’s broken. Sounded different and less frequent than yours though.

 

Yeah mountainpete just suggested the same thing. I've removed the bumper and it still clunks

 

Ah - that changes things

Barring hand checking for anything obviously loose like skidplates or other bolt on stuff, motor mounts and battery tie down are the first non-suspension places I would look.

 

Yep Ben is my go to. I thought of that as well but from what I've been able to see they look fine and the engine doesn't move more than usual when it's revved up.

 

Myself and other mechanics have checked every accessable bolt and component in the engine bay numerous times. Absolutely everything is secure.

 

I have noticed those runner bushings allow for more movement than I would expect but banging on those parts hasn't even began to make any sort of a clunk. I guess it's a cheap item to elimate though.

This clunking just sounds like a very substantial part, not something lightweight and/or flimsy

 

WAG:
Coilovers topping out @ full extension?

 

I considered that but it occurs on bumps that don't come anywhere near full extension. The video is of me driving over some small dried up mud ruts.

I can hit whoops at significant speed and even jump the truck without hearing this sound.

 

Yeah that's basically what I've been doing for the past 6 months. I frequently take this thing to pretty remote areas without cell service and some places that would be very difficult to get towed from in general so letting it continue like this has me worried

 

I had mine on a frame machine and the owner swore they weren’t broke, no excessive engine movement, took up close pictures of them etc., but he didn’t lift the engine. Made him lift it and driver side was broken. Agree probably not the motor mounts, doesn’t seem very common. Did you have to remove the front crossmember?

 

Well guess that's the next place I'll look.

Actually now that you mention the front crossmemeber I did have 5.29's installed shortly before the bumpers and this clunking sound began so I'm sure it was removed in the process.

 

Doesn’t sound like a suspension clunk. Definitively not metal on metal. Have you checked the drive shaft? Does it sound the same if you engage 4HI or 4LO?

might be worth getting one of those acoustical troubleshooting kits where you install microphones in the undercarriage to pin point noises or mount a GoPro underneath?

 

What skids do you have? There are a few threads about the TRD pro and rci skid making a clunk. My truck just started making this sound and the only thing I changed recently was adding rci skids. You can check that the bolts are tight, but the frame flexes and makes the pop. Mine does it when turning right, more when going in reverse than forward. Have you heard it with the skids off?

 

I almost forgot but don’t think Ben would miss it. On my clunk find quest, one was the rubber washers were damaged/missing from the top shock bearing with same Fox coilovers. Figured worth mentioning.

 

Clunking occurs in 2wd 4hi and 4lo. I've thought about the GoPro thing, but I don't even know where I would begin

 

Nope no sway bar

 

Haven't had skids on for months after a run in with a dear crushed my bumper/engine skid. Clunk is still there

 

Crossmemeber bolts are definitely tight. I'll take another look at the shock eyelets but from what I can tell they are fine. My next step will likely be suing this clunking sound as an excuse to upgrade to 3.0 Kings

 

King 3.0 is a good idea. The shock missing the washers would clunk wiggling it.

 

Oh you're talking about those centering washers. No there is no movement side to side or rotational in the shock ends

 

In the video, it sounds like something inside of your cab. Like the head unit moving within the dash trim, or something similar. Could it be your radio or perhaps another one of the computers within the cab of the truck that are bouncing around? Anything in your glove box. In all honesty, it sounds like a pistol rattling around in the glove compartment. Just saying, you’ve all but exhausted the exterior options (according to your posts). Maybe you could check the interior of the rig and find something you weren’t aware of..worth a shot. Good luck.

 

Absolutely.