Noise from rear end suspension or loose truck bed?

[HighCountryTremor]

I have a 2026 F250 Lariat Tremor with the 6.7 HO. The truck has ~3k miles. Upon entering/exiting the truck cab and bed while I parked I hear a popping or small clunking sound coming from the rear/bed of the truck. The issue happens around 70% of the time. It can be recreated by rocking the tuck bed or running board. I took the truck into the dealership and of course it wouldn’t make the sound then. The dealership double checked the torque on all of the bed bolts and suspension components and couldn’t find anything. Once I got home from the dealer that day, the noise returned (of course). I have tried to pinpoint where the noise is coming by crawling under the truck and rocking it from but can’t figure it out. Could the aluminum bed be warped to where it pops in/out? Loose bed bolts? Bad rear shock or connection point? Hitch and spare tire appear to be snug. Not a huge deal but annoying when these trucks cost as much as they do. I have included a video highlighting the noise. Any tips or similar experiences would be helpful. Thanks all.

 

[The Evil Twin]

I happen to be in the shop when I saw this. My truck does not make a similar sound. The only thing that I do hear is the safety catch on the bed cover (Diamondback) rattle.
Totally feel ya though. There is a squeak my truck makes on small quick hit bumps. Irritating AF driving with the windows down on country roads. Dealer cannot replicate

 

[Poor White Boy]

Check tailpipe mounts are installed correctly

 

[Canyon Trekker]

Maybe the shocks. Mine had a rattle since day one.

In the past, there was a slurry of mechanical noise issues caused by the Tremor stock shocks. I had a problem where I could hear a rattle in the rear when simply rolling gently down the road and the dealer could never figure it out. I complained about it at every service interval and asked about the shocks since it had been an issue with so many others, generally describing the noise as a "clunk". They did check the shocks and said they were OK. They even said they duplicated it on the test but couldn't pinpoint it; even replaced the leaf spring pads to no avail. I just learned to live with it since new in 2022.

Well, I recently replaced my shocks before the Moab meetup with a set of Fox HTOs and wouldn't you know it, the rattle is gone. But I could physically hand shake the old shocks and no sound. It only made noise when rolling or hard bouncing the back by the tail gate.

Edit: I didn't see the video until after I wrote this; sounds like something heavy moving. Is the spare tire pulled up tight?

 

[Optimus🤖]

Mine sounds the exact same but only when I'm taking care of business in the backseat!

All seriousness aside, there are a few classic Super Duty culprits that dealerships almost always miss because they just throw a torque wrench on the bolts and call it a day.

Here is what I'd check next to isolate it:

1. The Tailgate Striker Pins / Latches (Easiest Test)

Rocking the bed side to side can reveal that the noise is actually coming from the tailgate.

The latches rubbing on the upper pins can make a sharp squeaking or popping sound.

How to test: Drop your tailgate so it's open, and push on the side of the bed to rock the truck exactly like you did in the video. If the noise completely disappears, you've found the issue.
The fix: Spray the pins and the latches with lubricant or grease to quiet them down.

2. Leaf Spring Isolator Pads (Most Common)

The dealership checked your u-bolt torque, but the noise is often the leaf springs themselves.

Dirt, grit, and road debris entering the spring pack, or dry factory contact pads, will cause a popping or clunking sound as the suspension flexes.

How to test/fix: Jack the rear of the truck up so the axle droops and the leaf springs are almost maxed out.
Clear out any debris and apply grease or spray lubricant to the rubber pads between the first and second leaf.

3. Defective OEM Tremor Shocks

Even with low miles, the factory Tremor shocks are notorious for making a clunking or knocking sound when they fail.

The dealership checked the mounting bolt torque, but the shock itself can be the culprit.

How to test: Have someone rock the truck just like you did in the video while you crawl underneath and firmly grab the rear shock bodies. If it's a bad shock, you will often feel the "pop" vibrating right through the metal cylinder.

4. Dry Leaf Spring Bushings

Sometimes the leaf spring or shackle bushings can be dry and cause a thunk or pop.

The fix: Lube up the bushings; many owners have had this instantly cure their rear-end popping noises.

Try dropping that tailgate first since it only takes a few seconds, but my money is on either the tailgate pins or the leaf spring pads needing a quick clean and lube.

Good luck and keep us posted on what you find!

 

[HighCountryTremor]

Thanks for the tips, all. I will investigate those this week. Here is video if it helps narrow down the issue. It only takes very minimal rocking to make the noise. You can do it by just using your fingers.

 

[The Evil Twin]

Thanks for the tips, all. I will investigate those this week. Here is video if it helps narrow down the issue. It only takes very minimal rocking to make the noise. You can do it by just using your fingers.

now THAT sounds like a shock.