Mysterious Clunk Under Driver Side Floorboard

A few months ago, I started noticing a subtle clunk coming from underneath the driver's side floorboard. Here's what I've noticed so far:

I can feel it more than I can hear it. The clunk happens while going over uneven bumps. What I mean by "uneven" is that the driver side hits a bump and the passenger side doesn't (or vice versa). For example, potholes can cause it but speed bumps typically don't. I can feel a clunk under my feet. I haven't noticed any adverse effects while driving, just the clunk.

If I ride in the passenger seat and have someone else drive, I can't notice it (neither by listening nor feeling).

I don't hear it at speeds over ~35 mph, but that could just be that I can't notice it over road/wind noise. The *clunk* feeling also seems to go away at speed. I figure since it's not made worse by engine RPM or wheel speed, it's probably suspension or steering (i.e. not worn engine/transmission mounts, etc. that would get more noticeable with wheel and engine speed).

It's much worse when it's cold out. I can hardly hear or feel it if it's over 55 degrees outside. Below freezing and it's very apparent. This makes me think it might be a worn rubber/plastic bushing somewhere that gets particularly unhappy in the cold.

I've checked the torque on control arms, track bar, and shocks. They all were at spec.

I also gave a quick look at the control arm bushings (I have Synergy control arms), but they didn't look bad. I'll take another look this weekend, though. I'll also check the track bar bushings and anything that I can get a torque wrench on.

Any other possible culprits I should look at while I'm under the heep?
 
Don’t neglect to check the trans mount or motor mounts or the rear suspension components. The vibrations felt or heard under you might not always be located in the place you’re hearing or feeling it from.
 

Slimebones

Active Member
Don’t neglect to check the trans mount or motor mounts or the rear suspension components. The vibrations felt or heard under you might not always be located in the place you’re hearing or feeling it from.


True that. Sounds can travel "through" metal components, occurring at opposite ends. Also check rear components for tightness (if you haven't).
 

Bierpower

Hooked
I was getting a clunk that sounded like it was coming from my floorboards. Finally realized it was the shackles hanging on the back of the frame. Don't ever narrow your options based on where it sounds like it's coming from.

Sent from my Pixel 2 XL using WAYALIFE mobile app
 

nbunga

Caught the Bug
Make sure there isn’t anything bouncing around in the floor well cubby in the back where the jack is.
 

wayoflife

Administrator
Staff member
A few months ago, I started noticing a subtle clunk coming from underneath the driver's side floorboard. Here's what I've noticed so far:

I can feel it more than I can hear it. The clunk happens while going over uneven bumps. What I mean by "uneven" is that the driver side hits a bump and the passenger side doesn't (or vice versa). For example, potholes can cause it but speed bumps typically don't. I can feel a clunk under my feet. I haven't noticed any adverse effects while driving, just the clunk.

If I ride in the passenger seat and have someone else drive, I can't notice it (neither by listening nor feeling).

I don't hear it at speeds over ~35 mph, but that could just be that I can't notice it over road/wind noise. The *clunk* feeling also seems to go away at speed. I figure since it's not made worse by engine RPM or wheel speed, it's probably suspension or steering (i.e. not worn engine/transmission mounts, etc. that would get more noticeable with wheel and engine speed).

It's much worse when it's cold out. I can hardly hear or feel it if it's over 55 degrees outside. Below freezing and it's very apparent. This makes me think it might be a worn rubber/plastic bushing somewhere that gets particularly unhappy in the cold.

I've checked the torque on control arms, track bar, and shocks. They all were at spec.

I also gave a quick look at the control arm bushings (I have Synergy control arms), but they didn't look bad. I'll take another look this weekend, though. I'll also check the track bar bushings and anything that I can get a torque wrench on.

Any other possible culprits I should look at while I'm under the heep?

Check your transfer case and exhaust especially at the transfer case skid. Could be it got dented up from a wheeling trip and now the two are sitting really close together now. This will cause your exhaust to make contact with it and that can be felt inside. Check the hangers as well as if one is off the rubber bushing or the bushing is worn out, that can allow things to swing around and make contact with things as well.
 

jeeeep

Hooked
Check your exhaust especially at the transfer case skid. Could be it got dented up from a wheeling trip and now the two are sitting really close together now. This will cause your exhaust to make contact with it and that can be felt inside. Check the hangers as well as if one is off the rubber bushing or the bushing is worn out, that can allow things to swing around and make contact with things as well.

This ^^ i had the same clunk on my 2010 and while the cross over pipe visually did not appear to be touching the skid, putting a screwdriver in the gap i was able to see how much movement there was.

Made some adjustments and no more clunk.
 
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