NVH - that's the acronym you want to remember - Noise, Vibration, and Harshness. I found tools that will help you with these, but first I have to drag you (kicking and screaming) through how I found them.

Stinky has a vibration that I was unable to isolate because of other vibrations, shakes, and noises throughout the truck. Well... megablasts from the Buck$Zooka and many weekends of wrenching narrowed the list down to 1 or 2 sources.

Problem 1, which is minor - but may be a clue to problem 2: Front-end vertical shudder. Under the right conditions, I can get an oscillation in the nose - not unlike strumming a taught rubber band (but slower). I just charged the GoPro yesterday and found my mounting hardware, I suspect I may see the front axle oscillate back and forth a little.

Problem 2: I feel a vibration under there, and it's strongest in the steering wheel. A beverage in the cup holder indicates it feels it too. My foot can pick up the vibration in the pedal, but feeling hard surfaces throughout the truck - it's not as strong as in the wheel or my foot. My wife would never know it's there. After working closely with pirate4x4_camo in emails, I've paired down the information "noise" (focusing on key clues):

• 44 MPH is the sweet spot for this vibration/noise (most intense), but it is all the way up the speedo from about 41 MPH
• Coasting downhill in neutral and revving up had no effect - it is speed-dependent.
• It fades a bit on parts of the road, and comes on strong on others. I've focused on the sections of road where the changes occur - they are always the same stretches of road (after three days of testing). One other possible clue: Those sections of road have a weird wind dynamic (I'm driving in the Columbia Gorge). Side-loading may be at play, but I have to confirm.
• It's either an old vibration that's getting worse, or the old stuff is gone, and this is new in response to the work done to Stinky. For those about to ask - everything that spins under the truck is new within the last 3 years. Everything. I'm not kidding. The only original moving parts down there are the springs.
• There are so many new parts on Stinky that it is near-impossible to say "It started after I replaced XYZ" - so I can't use that as a troubleshooting tool.

There... I finally got to the point when I said "troubleshooting tool". NVH sensing technology has reached your pocket. Really. Literally. Today's smart phones and tablets have motion sensors and microphones - everything an expensive NVH recorder needs ($5000 is common). Now all you need is an app to tap into those sensors, and you have an NVH recorder in a pocket. Thanks to pirate4x4_camo leading me this way, I found the following:

• Bosch (yes, the same people who make our fuel pump) iNVH for Android phones. You'll find that free on Google Play.
• Sonoscout NVH Recorder. This one is for the iOS crowd, and I know little about it.
• Trelleborg Shim Selector. This one "sounds" rudimentary, because it's for recording brake noise - but hey... it works on Android and iOS.

I will just bet many more will be available soon - maybe even as a feature in an OBDII app. That would be cool to log NVH data with engine data - you can at least learn if the NVH peaks with speed or RPM.

 

I'm following this thread, may prove helpful downroad..

 

Nice, this will be interesting. Are you still suspecting the ladder bars to be an issue?

 

Not that it really matters or anybody cares but my name is Camo, the user name on FTE was already taken when I joined. So I just put my company name before my name.

Anyhow, I went and found a older Android phone so I can get the app and play along. Doesn't make sense for me to have different software if we are gonna go down this road.

 

Tugly,
From your description and what I left above I would advise checking your front track bar before you get too involved.

What it sounds like to me is mild case of what is referred to as the "death wobble" in the jeep world. I have had it on my TJ after a lift install. The truck being so much heavier may be helping subdue the effects that you see compared to the jeep. My problem was my trackbar loosening back up after a couple of weeks of driving. Torquing it back to spec and life was good again.

Hope it helps.

 

have to subscribe interested in where this goes also

 

Subscribed- we deal with this at work using the big money sensors and acquisition systems... it'll be neat to follow and see if I can help!

 

The track bar is one of the new things, I will check if it has worked loose.

I downloaded the iNVH app to my wife's phone (she has an Android, I'm stuck with an Apple). I will also try to load it onto the Nexus 7, but the website says that won't work.

I was set up to do video under there this morning - until it rained. Maybe tomorrow.

 

I took 2.7G of video under the truck (front and rear) with 720P resolution at 60 frames per second and analyzed the data. All I learned from that is everything looked good on the rear suspension - so I no longer believe the ladder bars are binding. I'll try to trim down the file size of the video of the front suspension and post that up, because the front suspension is a mystery to me.

I watched the driveline, and I could see nothing amiss there. Whatever this is, it's going to be detected by something other than video... just like pirate4x4_camo warned me.

 

Man... this took a long time to sort out. It's a huge file because it was recorded in HS (you can play it at half-speed with smooth video) and hi-def. "The Tube" reduced my resolution, and I could only mount the camera sideways with the hardware in-hand - so I had to wait for YouTube to process the video 90 degrees CCW. It's not the ideal situation, but it works.

This will probably be the most boring 9 minutes of your life, so I'll note where things change a little: First minute and a half, 2:35, and the last minute. Ta-daaah. If you've had a gallon-o-jo and want to scrutinize every movement of the suspension and steering hardware, have at it. Leave a note for the EMTs, so they know what induced the coma... and they'll know to divert their eyes from the screen, lest the same fate befalls them.

 

without even playing the video I see a potential issue, not likely to be the root cause of the 44 vibe you are hunting but possibly associated with the shudder down under you mentioned.

 

LMAO,,, trying to find a vibration with video is the equivalent of using a bazooka to cure the flu virus.

 

what do you see?and thanks for for all the information you have shared in this and the other threads

 

I am just the trail guide on this adventure, lets give Tug the oppertunity to make the discovery I am the Tenzing to his Hillary

you're welcome, as much as I enjoy learning new stuff sharing the info is the real reward for me.

 

I spotted it too... if you are referring to the shackle at the end of its play. That means collapsed spring. I looked hard at it, and the axle mount is above the spring eyes - bad juju.

I found one other thing that's messing me up: I have this $5 mechanic's stethoscope and I'm on the rampage with that thing, driving or idling. I put it to the steering wheel and the windshield (glass is the ultimate sound transmitter) - everything rotating sounds like perfection.

I reported a growl during idle the other day (new to my ears, but I avoided driving Stinky for a long time to freshen up my patience and perspective). I was putting the stethoscope to the exhaust system, and I heard this horrendous cyclic "fart" in the resonator. This is actually a form of resonance that the device is causing. Son of a..... I move the probe upstream and downstream of the "windbreaker", and the offending noise is all but gone. There are strange dynamics taking place in there, and my fingers are walking all over my smart phone for the nearest muffler shop with an opening. If all else fails, I have one of these in the truck: