Sportfloor

New to diesels and Dodges. Have a vibration of sorts more of a light thump that can be felt ( not heard) in the gear shifter, steering wheel, and accelerator pedal. It is fairly light in wheel and accelerator but pretty noticable with hand on shifter. It happens from about 1,800 - 2,100 RPM and seems to lessen coasting and worsten accelerating. It is by far the worse in 6th gear but can be felt in 5th. I thought it was probably drive shaft problem but was able to get the same vibration parked with trans in neutral with clutch in or out. I have an appointment tomorrow to get it checked out and am dreading them telling me its normal. It kind of takes the fun out of having a new truck. By the way this is with the AC off, if its on it really shakes, you can actually fell the compressor kick on and off. Anyone got any ideas?

MikeyB

This is normal for the Cummins. Mine does it but now it's not as noticable after putting several thousand miles on it.<br> The same for the A/C.<br><br>MikeyB

t-15 firefighter

the only time i can feel a vibration is when mine is cold. not really a vibration just seems to run a little rougher. once it warms up to normal operating temp everything smooths out just fine. i can really feel the a/c compresser kick on though. it is really pronounced. doesn't seem to effect anything though.<br><br>enjoy your truck. you will love it ;D

Badunit

What you describe sounds like what my truck does too. I have 4500 easy miles and I'm hoping a little more break-in will smooth it all out.

pwabbott

If anyone doesn't feel A/C kick on, There's is broken. <br>If you want a vibration free vehicle, shouldn't bought a Diesel. The quieter 03 Cummins is quieter because engine has less vibration. More break-in means less internal friction for that explodin #2 to overcome. All vehicles have certain speeds and certain RPMs where vibration increases, more noticible. These are know as natural frequencies of vibration where every part in the drive-train seems to vibrate in harmony like and orchestra playin an overture. Man you got that Cummins HO Orestra under your hood playin away, enjoy it.<br>

Sportfloor

Thanks everyone for the help. I am getting used to the normal diesel vibrations which I would call more of a buzzing? I don't think what I have is normal or part of it being a diesel. I drove to work this morning into a head wind which put a little more strain on it and the thumping was worse, its more of a thump, thump, thump all be it fairly fast and you could feel it in the floor and seat as well. The engine is smooth hot or cold and I haven't been able to repeat the thump being parked again. The truck has about 1,600 miles and the thump is getting worse not better. I figured if it was a break in thing it would be getting better. I am taking it in this afternoon to see what is going on, maybe I'll drive another one and see if it is the same.

FiverBob

Are you possibly hearing the thumping of the dually axle? My dually thumps much more than my single did. I expecially hear it from about 50 to 75 even when the road seems very smooth. If I were worrying about it, I could call it a bearing vibration. I am not worrying - - - - yet. <br><br>SuspiciousBob

Sportfloor

Went to the dealer yesterday and mechanic test drove it and was not impressed with the vibrations but couldn't really pin point what he thought could be causing it. We drove another six speed HO QC but it was a SB SRW just to see what it did. It did have some of the same things accelerator vibration was worse, gear shift was more of a vibration than the thumping I have and not nearly as bad, and there was nothing noticable in the steering wheel. He agreed mine was worse overall and could see why I was concerned. Said he would check into it and give me a call. He also admitted that he hadn't driven a lot of the new diesels but agreed that the vibration was more than he would expect from a new truck. Fiver Bob I don't hear any noises its all feel. I think I might go try to drive a few more and see how they are. Well we'll see what happens next. Thanks again for all the help. The wife is going to get the tags today, I don't even want to see what the sales tax cost on this thing, ouch.

pwabbott

Unfortunately there is little that can be diagnosed from vibration unless the vibration is severe. All vehicles will have certain ranges of speed where their normal vibrations are more pronounced. Usually vibrations that are should be of concern are accompanied with a sound that help to identify a problem. If the intensity of the vibration changes write down when it happens, RPM, how long had the truck been running, type of road, etc. <br><br>If you can take Tech to location where the behavior is most pronounced/severe they can observe better for themselves.<br>It sounds like your Tech/Dealer doesn't have much experience with Diesels from what you said, &quot;He also admitted that he hadn't driven a lot of the new diesels but agreed that the vibration was more than he would expect from a new truck.&quot; This is a clue to look for a volume dealer that sells many Diesels, therefore, is likely to feel confident in diagnosing your problem.<br><br>An inexperienced tech is not likely to want to tear into your truck unless he is confident in what he is doing. So look for a new dealer, even if you need to travel many miles. It will save you time and grief.<br><br>BeenThereAndDoneThatPhil<br>

Badunit

It's possible it isn't getting worse, you're just more attuned to it so you hear it and feel it clearer now. I can't tell you for sure if mine had it new (I don't recall that it did but it might have) and it got worse or that I just got better at hearing it. I also can't be sure if it is now getting better or I'm just getting used to it. I am nearly convinced that it is an exhaust system resonance but others say it will go away after a while. We'll see.

pwabbott

Vibrations usually get worse with age, they kinda graduate from one grade to the next.

Tob

If it sounds like you have a helicopter in the cab then you probably have the rear windows partially open. All crew cabs do this and it sacred the heck out of me the first time it happened. There is some mention of it in the owner's manual.<br><br> There is also a resonance around 2000 rpm which has been previously referred to as 'boominess' which (I believe) all of these trucks have to one extent or another.<br><br>

pwabbott

[quote author=Tob link=board=20;threadid=14925;start=0#142399 date=1054017042]<br>If it sounds like you have a helicopter in the cab then you probably have the rear windows partially open. All crew cabs do this and it sacred the heck out of me the first time it happened. There is some mention of it in the owner's manual.<br><br>[/quote]<br><br>Tob , it is not just &quot;crew cabs&quot; do it. Back in 78 had a small, four door econo-box auto. One day driving down the freeway a kid in back seat cranked down the window just behind me. It sounded like a turbo-prop had just landed on the roof. I thought my eardrums were going to break it was so painful. Strange thing about the sound, If you were sitting in the back seat it wasn't loud at all. <br><br>Dogs and kids are alike in one thing, they both like to stick their heads out the window of a moving auto with their tongues hanging out to dry.

Sportfloor

Thanks again to all, no its definately not the helicopter in the cab problem. We also have a 1999 crew cab chevy one ton ( company truck) and I know all about that sound when the kids are in the back, thank heaven for the window locks. Bad Unit you're probably right it probably hasn't gotten worse I am just fixating on it. I pulled my gooseneck with a tractor on it about 50 miles last weekend with trailer and tractor being about 14,000 lbs total. The truck pulls great and seemed to have slightly less thumping, but not really much different. Sierra Phil I don't really consired the vibration severe just annoying as hell. Good advice to keep track of the conditions that it does it worse in. anyone have any dealer in the Kansas City area they could recommend? The tech that drove it seemed fairly knowledgable but they definately aren't high volume and they probably don't see a lot of the new trucks for this problem. Can anyone expand on this resonance? Is it a noise or vibration ? I think I'll go drive a few more just to see how they are. Thanks again.

GrandpasRam

If it is a pronounced thumping that is not accompanied by much noise, I had a similar problem occur on my old '78 GMC 4x4 years ago. It turned out to be the drive shaft bearing had dried out a bit, and had to be replaced. If you look under the truck, between the transmission and rear diff there is a bearing assembly the driveshaft goes through, and it may have been installed with too little grease in the bearing. Just something worth checking, as I remember having that one replaced back then and it made a noticable difference. FWIW.