10Ram,
if you have just the noise, its most likely the torque convertor. (star case issue)
If you DO, have the TC replaced, i`ve read some complaints that the new TC may cause the MDS vibration(s) to all of a sudden appear. Be on the look out for that, i would surely like to know if that happens to you if you decide to get the TC replaced.

Now here is what i think happens with the trucks that didnt have the MDS vibe`s, and then some all of a sudden have the MDS vibes AFTER the TC got replaced... As vibrations can change locations, AFTER a piece or a part gets replaced, it change`s the reaction to how it happens when the new parts were installed. So now, the new TC is in the tranny, now the torsional vibes have a new way to travel along different paths. Sometimes these vibrations can die in certain area`s and be created in a different area and then you have vibes you didnt have before. Think of this scenerio as changing the location of a wheel weight on a tire. Everything was good until the wheel weight got re-postioned and now throws the wheel out of balance. I could only come up with that particular type of scenerio to explain what i meen when the new TC MIGHT cause the MDS vibration in the steering wheel, seats, gas pedal, to appear. This is why i think some people experience it when the TC gets replaced and some dont. These 4th gen trucks are VERY sensitive to vibrations. Anything you do can cause a different reaction.

My ballast update for 1-12-12 (for the MDS vibe/buzzing issues)
This morning, i removed ALL the ballast`s from my test truck, MDS vibe is back with a vengence. (terrible vibes in the seats, steering wheel, gas pedal, and also noticed the floorpan had terrible vibes. Felt it right thru my workboots very badly) So, i put the ballast`s back on the truck, MDS vibe`s died again. I did NOT feel one single thing vibrate. I`m onto something here guys, and like i said, i just need to perfect it and then release the info to you guys and hope it works as good for you as it has for me. I will keep everybody updated as time goes by.

Just a word of advice, the ballast will NOT make the TC noise go away. Thats a whole different issue by itself.
If you have the TC noise, thats caused by a loose fitted spline shaft into the turbine hub inside the torque convertor.
The only fix for that is the STAR CASE report/bulliten

Thanks for your time and info guys. It really helps me alot into figuring this all out.

 

Thanks, i appreciate the comment. Yes, very true, we`ve not seen eye to eye on several ocassions, but i surely dont come in here to mislead people, i try to help them with the 40yrs of knowledge i gained over the 40+ years of turning wrench`s in dealerships. I dont claim to know it all, but ther are things that work for me even if it dosent make sense to someone else. Maybe my advice or statements might not agree with others from time to time, i can only hope it helps some people in the meentime no matter how weird or strange it seems to others. I hope that you an i can always add to these forums and agree to disagree in a nicer manner for both of us from now on. I think we BOTH have alot to offer... sometimes we may disagree, but thats not always a bad thing either. Alot usually depends on how the other person takes it.

As for the MDS vibe issues and the TC issues, i`ve probably tested and drove more trucks with these issues than most have on these forums. So i`m just trying to find something that will work and hopefully help everybody here. What i`m doing is on my dime, and whatever is spent is out of my pocket and my time. If it helps just ONE person on here, thats the payoff for me. I will never stop testing things that might solve a problem, thats just me. I wont let it defeat me.

 

I will keep a "feel" out. I had to reschedule my appointment so the TC will be replaced next monday.

 

Got a picture of these ballasts and where they are mounted? It would be interesting to see what the difference is between people who currently don't get MDS vibes and those who do. If they are mounted to the frame as I suspect they are, then it seems plausible that things like side steps could make the problems worse/better.

 

Some time ago in a different post, I questioned the frame design as having some kind of resonant or parasitic frequency that induce oscillations. My observation was based on the fact that Dodge has those heavy weights on the frame and the only explanation I could come up with is that they put them there to dampen the oscillations. I wondered why, Chrysler would spend money on weight savings (aluminum hood) and then go and mount those heavy weights on the frame. I've never seen anything like that on any of my other vehicles. My point of reference is based on having spent many years and hours qualifying military designs in environmental chambers to simulate fighter aircraft real life conditions to validate designs in pre-production HW. We used to mount accelerometers to various locations and monitor their outputs while the HW was mounted on vibration tables. We would then perform surveys for parasitic and resonant oscillations in all three axis under multiple G forces and frequencies. We would subject the HW to random, pseudo random and specific frequencies on the hardware. The data was then reviewed and we would find design deficiencies that would need to be corrected and retested. My guess is that the frames for these gen4s have some issues that, based on various parameters (bigger tires, sidesteps, factory assembly variations, engine behavior variances, etc) may manifest themselves in the different symptoms described here. Chrysler probably was under the gun to get the truck out and they tried to fix it under economic pressures so they added the weights as a band-aid. So it does not surprise me if adding ballasts changes the characteristics of the frame behavior.

Mind you that this is all speculation based on my many years working in production engineering and I am not claiming to have any answers.

 

Most light-duty vehicle platforms will have some sort resonance response issue, just some worse than others. In many cases these resonant frequencies are dampened by the time the entire body attachments come together.

Dampening techniques have been used in the past by a number of manufacturers. The older Lincoln Mark series ('70s) had dampeners strategically placed in various locations on the body, for example.

Although beam and torsional rigidity on the 4th generation Ram 1500 series is much higher than their previous open rail frames, they are also much lighter. Heavier, thicker steels can usually contribute to the dampening of low frequency harmonics or sympathetic oscillations.

Anyone heard of this complaint on 2500/3500 series Rams?

Regards,
Dusty

 

The 2500/3500 hemi trucks dont have MDS, so they aren`t prone to the MDS torsional vibes. I have yet to test drive a 2500/3500 with any vibe issues, but the TC is a different story, have heard some with the TC rattling issues.

 

I'm wondering if the MDS vibrations on the 2WD trucks and the vibrations on the 4WD leveled or lifted are related. It may be worth a try to apply the same ballast to the lifted 4WD trucks - just a thought.

 

Good catch pedro, i didnt even think about adding to the thread that i had road tested 3 ram 1500 (4x4) trucks that were lifted. 2 of the trucks had horrible vibes, but i`m not sold on the fact that it was MDS related because the lifted trucks didnt feel right to start with, so to be fair, i would have to say that they dont count into my theory & diagnoising the actual vibe issue that i`m looking for in the 4th gen MDS trucks. I`ve also test drove a few 2wd hemi trucks, they too, have the MDS vibes just like the 4x4 trucks do. All these trucks vary on how noticable the vibe is. None have been equal in the amount of vibrations as far as that aspect. Just seems to be hit and miss with these trucks.

 

Got my TC replaced today, seems to have fixed the "rattle" noise!

I can tell a difference in the drive of the truck, seems tighter (for lack of a better word).