does anyone have any ideas what this clunk could be?? in my truck in signature, 2003 F350 CCLB 4x4, 4" lift. its only low speed, on very light bumps. really does it when the truck flexes, like turning into an elevated driveway or something. driving me absolutely insane the last few months. it sounds like its coming from right under my feet

-removed front shocks and drove
-removed front sway bar and drove
-front wheel bearings are new and tight
-front leaf spring, rear upper shackle bushings are new (thought that was problem..no)
-front leaf springs and bushings are new, although i suppose its possible to have a bad bushing already
-removed traction bars and drove
-removed front track bar and drove, but going to try this again.
-all cab mounts look ok
-took out cab mount under drivers foot, and cut down the metal piece a little...read about it on another thread on here. no change
-made sure my gooseneck ball couldn't rattle
-steering box is new...thought that was it
-steering shaft is solid
-transmission mount bushing and crossmember feel tight
-lubed front driveshaft slip joint and it doesn't have any u joint play
-rear shocks seem ok but haven't removed them yet
-fuel tank is solid
-rear driveshaft has new carrier bearing and u joints, all is tight
-exhaust is not hitting anything
-u bolts all tight, spring bolts are tight

as you can see, i've been through damn near everything. my only thoughts right now is a possible bad cab bushing, or bad leaf spring bushing...as it sounds like its right under my feet. and when you flex the truck, it makes all sort of popping and clunking noises. i had the truck on my buddies lift and we went under it for an hour yesterday looking around with no luck. only thing i found was a bad traction bar bushing but we removed them and it still does it..

most noticeable at the end of the video...it sounds exactly like a bad sway bar bushing but thats not it

 

Try the motor mounts or trans mount. The engine will lift up when under load and drop back down with a thud. Put it in drive and hold the brake pedal down while putting a load on the engine. You should be able to see the engine lift up from the left side.

 

Ball joints.

Recently helped service the front end on my dad's truck. It too would clunk at lower speeds, turning or slight bumps. Turned out to be the driver side top ball joint and passenger bottom ball joint. Both were shot.

 

I jacked up the truck and checked for play in the ball joints and didn't see any, but not sure if I can totally rule them out

 

I'm having the same exact issue, have you tracked down the problem?

 

Check all body to frame mounts. The core support mounts and cab mounts are somewhat known for this. Put a wrench on the mounts and a prybar. They can visually inspect ok yet still be lose or internally deteriorated. If they check out ok start looking at chassis bushings. A chassis bushing can visually inspect ok yet in fact be bad once the attaching components are disassembled and you can get a good look at the rubber or metal shell.
What about the batteries are they clamped down good? Spare tire loose? A component in the engine bay flopping around? It sounds shock related when I zero in on the noise. Difficult to zero in online.

 

I towed a trailer 120 miles and it stopped clunking. So...idk lol

 

Do you still have the spare tire mounted under the bed?

If yes make sure it is aired up an ratcheted up tight.

They can sound just like what you posted of loose/ low on air.

 

I do not have a spare tire

 

drove 700 miles to ohio with a loaded bed and 5k trailer...didnt clunk at all. soon as i was empty and headed home, started clunking just like before...

 

See red highlight

 

Removed fronts, no change

 

Did you check the anti squeak pads between the leaf springs? My dad's 2000 was doing that and one day I was looking for the sound and decided to lift the truck by the receiver hitch and then I used a brass wedge between each leaf and sure enough they were worn down to nothing and the spring was touching themselves. Added new ones and all quiet, I changed my 2004 three years ago and some were good some were worn down to nothing

 

I was having the exact same issue as you and chased it for months. I ended up replacing all 4 ball joints "just because" even though there was no play in the front end. I did realize though once I had the wheels off and everything stripped from the spindle that there was indeed about 1/4" of free play from the lower ball joints. Made a noticeable difference however it only removed about 50% of the "clunk" and something was still noticeably wrong. More and more troubleshooting and inspections made me discover that the lower shock bolts had "eroded" from the metal sleeves in the shock bushing sleeves. I went ahead and put in new shock bushing/sleeves and new lower shock bolts and finally...peace at last. No more clunk.

 

My next step in my "clunk" throubleshooting was going to be to grease the slip joint in my front driveshaft, I've read that once those get dry they can be noisy. After that I was going to do leaf spring bushings. Its tough to find the exact problem...