4th-Gen Mystery Clunk Solved! Not the fuel tank!!

[O.R.T.]

MODS, please sticky this!

What would you all say if I told you I believe I just solved the dreaded "Mystery Clunk" that we all have read about or experienced? I'll bet you would never think that the NVH Noise-Vibration-Harshness Bells would actually be the source of a noise! It's the bell working loose as the rubber isolator's shrink and wear and allowing the bell to clunk in the mount saddle. Grab a couple sockets or a breaker bar and an impact wrench and tighten it all back down to stop the noise.

I accept RootBeer as a "Thanks!".

 

[RoadRamblerNJ]

MODS, please sticky this!

What would you all say if I told you I believe I just solved the dreaded "Mystery Clunk" that we all have read about or experienced? I'll bet you would never think that the NVH Noise-Vibration-Harshness Bells would actually be the source of a noise! It's the bell working loose as the rubber isolator's shrink and wear and allowing the bell to clunk in the mount saddle. Grab a couple sockets or a breaker bar and an impact wrench and tighten it all back down to stop the noise.

I accept RootBeer as a "Thanks!".

And just where would one find this NVH thing that I've never heard of in 45 yrs of wrenching? Always good to learn new tricks!

 

[RoadRamblerNJ]

Nevermind. It's 3 am. I'm nleary eyed and missed your likn. See.

 

[Oldfireguy57]

Where is this located?

 

[usaf2006]

I believe there's one on each side underneath right about where the front driver and passenger doors are.

 

[chrisbh17]

I think Ive seen people report that removing them altogether didnt really change much in regards to how the truck acts, so you could potentially try running without them to see if you get the same results. Then no more worries about re-tightening

FWIW the ones on my 2017 can be turned a little by hand...not as loose as yours, but definitely might respond to some tightening down. I might actually run with them removed to see what happens (supposedly there are there to absorb some vibrations when going to and from 4 cylinder mode)

 

[O.R.T.]

Yup. I removed mine for the day. Found out the bolt is shanked and the nut hits the run-out so you can only tighten it down so much. Went out, got 4 stainless steel washers, hogged them out enough so they fit around the bolt and all the way to the bottom of the bells and reinstalled them. Either way it's solved.

 

[yortnodnarb]

If the rubber isolator wears and you tighten the thing down to the point it can't move, it's no longer serving it's function so you might as well take it off. A vibration dampener has to move in order to counteract the vibration it's trying to absorb/dampen. If the thing is rigid mounted and not allowed to move on the rubber isolator, you've affectively just bolted an unnecessary anchor to the bottom of the truck.

At least that's my thinking of how it would work. If that's way off, I'm sure somebody will correct me. That's the beauty of forums, there's always somebody looking for wrong people to right.

 

[O.R.T.]

I get what you mean. I only tightened mine down to the point it stopped rattling around. I even went with a specific thickness of washer to keep it that way. IOW - I have access to a 2017 two doors down so it was easy to get the feel of what mine should end up like.



I'm gonna be checking to see if the rubber is actually available as a part #.