Need Help Mysterious Clunk

[JD522]

My 2015 Ram Crew Cab 4x4, an oddball with 6'4" bed, has started making a clunking sound when I go over bumps, even when barely moving. It happens when driving straight. I can't say I have noticed it happening or not when turning. Oddly, I don't seem to hear it as much on taller bumps. It seems to happen more on short, sharp bumps. It sounds like the sound is originating behind me. My wife in the passenger seat agrees. My sons in the back seat say it sounds directly beneath them. I got under the truck and nothing seems to move by hand, though I don't know what things to try. The spare tire is tight. The exhaust pipes are secure. The only thing I see is a cable that looks like it goes to the brakes. It has a place right around the spot beneath the back seats where there is a joint and long bolt. Anyway, that cable/joint is free to sway 6" or more in any direction. I'm wondering if it clunking up against the bottom of the truck could be what I hear. What is this cable and should it be swaying like this or secured in some way?

 

[AkNoad2]

Sounds like the parking brake cable is hanging because the linkage at the parking brake itself is sticking, mine doesn't hit the bottom of my truck but it hangs down lower than it should. Try lubing the linkage for the parking brake and see if that frees it up.

 

[audiophile]

The cable is gor your parking brake. It will sway and as the parking shoes wear down it will drop slightly. Mine moves quite a bit as well but I have never heard a noise from it.

 

[JD522]

It is very possible it isn't the source of the clunk. It was just the only thing I saw that had free movement to smack into something else. I will have to do more troubleshooting...

 

[Lyle Longboat]

Check your upper shock bushings. If these get pinched or become old and brittle, the shock mount bolt will clunk when you go over the bumps as you described. Also, the shock top mount may be moving ever so little side to side and may only Move when you hit bumps, thus if you checked, may not move with push of hand. It happened to me and I chased that clunk around for almost a year. Finally got um!
Could Be loose as well!

 

[Daw14]

Sway bar end links ? Shocks ? Track bar ?

 

[Jeepwalker]

Good suggestions guys ...the first thing that came to my mind when reading the post was shock bushing or sway bar link.

OP, You'll just have to get under there and see if anything is hanging down. Wiggle the exhaust, shocks, push up/down on the front drive shaft CV joints (inner and outer). Check muffler and catalytic converter shields (I guess they don't usually 'clunk'). While you're doing the checks, it might not hurt to jack it up to raise each front tire off the ground and wiggle (violently) in the 6:00-12:00 positions to check upper ball joints and wheel bearings, and just for good measure the 3:00-9:00 positions for steering loosness. And while you have the wheel off the ground, I'd stick a pry bar or board under the wheel and have a helper lift it up/down while you watch for lower ball joint movement.

Let us know what it turns out to be

 

[NJMOPAR]

Does the 6.4 bed have a two piece driveshaft?
If so, it might be the carrier bearing.

 

[Green_Manalishi]

Something inside under the seat against the back of the cab?

 

[RangerWeaver]

I had a similar issue a few months ago. I had been hearing a clunking sound when hitting small bumps. Eventually, I found out that the passenger side front sway bay link ball joint has separated and the link was coming free and slamming into the ball joint whenever I hit a bump.
If its the sway bar link ball joint I recommend having either a Sawzall or hack saw ready. I had to cut off the joint to get it free.