Incessant Clunking from Rear Suspension

[dafuture]

I'm dealing with an intermittent clunk that's driving me crazy. It sounds like a hollow thunk, think old box truck noise. I think it's coming from the left side, as I don't notice it when I hit potholes/manhole covers on the right. Had it at one dealer, they claim to hear nothing. Next local dealer says earliest appointment is 1/9/25. Trying a third dealer coming up, but I can't keep spending days on this (it's a 30min drive each way).

Any idea of things I could check? Only mod in that area was some Fox rear shocks which I re-torqued recently, so I don't think that's the issue - but I'm all ears.

Just adding some info - truck has 6700 miles, with 4000 on the Fox shocks.

Thanks!

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[Gros Ventre]

Worn out U-joints will do that. Get under the truck and see if you can wobble either the front or rear driveshaft u-joints.

 

[My 2ND Ford]

I'm dealing with an intermittent clunk that's driving me crazy. It sounds like a hollow thunk, think old box truck noise. I think it's coming from the left side, as I don't notice it when I hit potholes/manhole covers on the right. Had it at one dealer, they claim to hear nothing. Next local dealer says earliest appointment is 1/9/25. Trying a third dealer coming up, but I can't keep spending days on this (it's a 30min drive each way).

Any idea of things I could check? Only mod in that area was some Fox rear shocks which I re-torqued recently, so I don't think that's the issue - but I'm all ears.

Thanks!

So something loose will clunk constantly, shock, sway bar, something like that. Something semi loose will clunk when forced to move. How many miles on your truck, are the fox shocks old/ high milage? You mentioned that you retorqued the shocks, it's possible a bushing is becoming worn and only moving with a hard hit. Does it make the noise at random times or does it happen on accel/ decel? Remember a noise can transmit thru the body and may not be coming from where you think it is. Good luck.

 

[dafuture]

Truck only has 6700 miles, shocks 4000 (and they were brand new). It's possible it's a bushing in the shock, but I'd be surprised if it failed so soon. Is there any way to tell without removing the shock itself?

I retorqued the shocks just to make sure they weren't loose (and the culprit). They were still torqued to factory specs when I tested them.

Noise isn't on accel/decel, I only notice it when the suspension compresses - we have a steep garage entry, when it bounces over the speed bump I hear it. Potholes, manhole covers, etc. Any impact to the suspension that causes travel seems to do it, whereas normal driving I don't hear it at all.

 

[dafuture]

Worn out U-joints will do that. Get under the truck and see if you can wobble either the front or rear driveshaft u-joints.

I'll take a look at that, thanks. I'd be shocked if the U-joints wore out so fast.

 

[Gros Ventre]

I once had a new strut/shock do that. It kicked my butt trying to ID the problem. Mostly because I didn't believe a new shock/strut was the problem. Only after every thing else did I conclude the strut was the problem. Once I replaced it... noise gone. So don't rule out that the shock is bad.

 

[Gros Ventre]

I'll take a look at that, thanks. I'd be shocked if the U-joints wore out so fast.

I agree, yet worth checking. I once replaced the U-joints on another truck and during the work one needle fell into the hat. I figured it out and got that corrected... but that might happen and not get fixed leading to an early failure.

 

[Ford Motor Company]

I'm dealing with an intermittent clunk that's driving me crazy. It sounds like a hollow thunk, think old box truck noise. I think it's coming from the left side, as I don't notice it when I hit potholes/manhole covers on the right. Had it at one dealer, they claim to hear nothing. Next local dealer says earliest appointment is 1/9/25. Trying a third dealer coming up, but I can't keep spending days on this (it's a 30min drive each way).

Any idea of things I could check? Only mod in that area was some Fox rear shocks which I re-torqued recently, so I don't think that's the issue - but I'm all ears.

Just adding some info - truck has 6700 miles, with 4000 on the Fox shocks.

Thanks!

Hi there! Will you send us a message with your VIN and your local Ford dealer? I can look into things on my end.

 

[dafuture]

I once had a strut/shock do that. It kicked my butt trying to ID the problem. Mostly because I didn't believe a new shock/strut was the problem. Only after every thing else did I conclude the strut was the problem. Once I replaced it... noise gone. So don't rule out that the shock is bad.

I agree, yet worth checking. I once replaced the U-joints on another truck and during the work one needle fell into the hat. I figured it out and got that corrected... but that might happen and not get fixed leading to an early failure.

Fair point. I'd hope it's not the shock. I bought the new in box from someone else, but I'd have no warranty. That being said I'd gladly eat the cost to stop this noise. I'm guessing I'd have to take the shock off and check the bushing?

Definitely worth checking the U-joints. So far Ford service has proven useless, so I'm trying to fix it myself. Just a pain doing this outside in the cold since I don't have a garage.

 

[Graygoose2021]

Check spare tire. Make sure rolled up tight.

 

[dafuture]

Check spare tire. Make sure rolled up tight.

I'll check that as well, though it would be odd for it to only be clunking with left side bumps. Just have to figure out where the tool kit is.

 

[Gros Ventre]

Fair point. I'd hope it's not the shock. I bought the new in box from someone else, but I'd have no warranty. That being said I'd gladly eat the cost to stop this noise. I'm guessing I'd have to take the shock off and check the bushing?

Definitely worth checking the U-joints. So far Ford service has proven useless, so I'm trying to fix it myself. Just a pain doing this outside in the cold since I don't have a garage.

Not necessarily. In the case I describe above, it was the internals of the strut. They were just bad. Never had that happen before or since. But it was a brand new strut. I could only tell that the problem was fixed when the new replacement fixed the problem/noise. Fortunately the place I purchased it from made good on the warranty, though they fussed at me about it. But truly, the only way I knew the noise was fixed was it went away with the replacement unit.

 

[VRFlyer]

I inadvertently caused a clunk that I could hear within the cabin after installing an under-seat tray unit. I thought something in the bed, driveshaft, or leaf springs (common in my 2014 when temps would dip into teens drastically).

The culprit, after chasing somewhat of a ghost was the rear LEFT passenger backrest never clamped back into its horizontal striker pin.

Dumbest thing ever. ?

 

[Gros Ventre]

Bottom line for new in the box from a friend but bad, write a letter to the manufacturer, offer to send the shock to them, and ask for a refund (for what you paid, if not sticker price). They may defer, but they just might...

 

[dafuture]

Not necessarily. In the case I describe above, it was the internals of the strut. They were just bad. Never had that happen before or since. But it was a brand new strut. I could only tell that the problem was fixed when the new replacement fixed the problem/noise. Fortunately the place I purchased it from made good on the warranty, though they fussed at me about it. But truly, the only way I knew the noise was fixed was it went away with the replacement unit.

Ah, I see. Well I'll keep that as a last resort if I can't find the culprit this week. I don't want to blindly throw parts at it if it's something else.

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