dieselnewbie

Just took the truck for a test drive and now I have a new theory on this problem:

Since new, my truck has had the mild drone that occurs between 65 and 70.

The drone completely disappears at 71-72 MPH and smooths out just like 50. Completely smooth.

When it's noticible the drone is never loud, and there is a tiny increase in steering wheel vibration, and I mean tiny, that disappears when you get to ~69 MPH. Then it's smooth as glass.

Interestingly, the drone is more noticeable on accel up thru the high 60's to above 70 and less so when you decel on down thru the high 60's into the low sixties.

And the faster you accelerate up thru that speed band the louder it is, the slower you accelerate up thru that range the less loud it is. It's directly proportional to how fast you accelerate thru that 5 MPH range (from 65 to 70).

And if you cruise at a steady 68 MPH (I tried this with the cruise control) the drone less then accelerating up thru that band.

So I believe it's the tires, at least in the trucks that have this drone in the 65-70 MPH range, of which there are more than a few.

The trucks with the major vibe problem, other than the drone, may have a different problem.

I believe that 5 MPH speed range is the sweet spot where the tires change shape due to the centrifical force of the spinning tire. Like watching a dragster slicks going from being very wide and low to being very narrow and tall when they punch it and spin them.

Only the dragster is much more exagerated of course.

I used to have a Jeep and it had different tire noise at specific speeds. Most of hte time they would sound the same but at certain speeds the sound (and vibration) would be different.

It would explain the increase in drone if you cruise thru that speed band faster. The faster the tires make that shape transition the more pronounced the noise would be.

Also, I don't think a drive train problem would go away completely at 70 MPH, to the point where it's just a smooth as it is at 50 MPH.

JMO of course.

When it comes time to change my tires I'll go for something smoother and see what happens.

Any ideas?

Comments?

DT.

BigBlue

Interesting theory. I'm wondering if it's not an exhaust drone. Never having heard this drone before (on mine I know it's the exhaust. 4" straight pipe ending under the bed) I can't say for sure.

i6DZUL

What brand of tries are you running? Size? Air pressure?

dieselnewbie

Don't know the tires off hand I6 but I'll look. It's pouring rain outside now.

BigBlue, it could be my exhaust, not sure.

I'm just trying to figure out why a little noise happens only between 65 and 70 MPH.

It could very well be the exhaust. I have the stock exhaust for a 2004.5 HO CTD short bed.

Like I said, I have a hard time believeing it's the drivetrain when the drone completely goes away at > 70 MPH.

At 70+ the truck smooths out like 50MPH, maybe even smoother.

How do you check if it's the exhaust?

Thanks,

DT.

Hannibal

That's normal engine vibration at around 2100rpm. Perfectly normal and acceptable. Mine did that as did my previous three Cummins. I wish that's all my '03 did. I really liked that truck. See gallery at left... I about choked up when I left it there while leaving in a truck I couldn't hear running. Like giving away a good dog because he barks constantly. It was a necessary evil in my court. As you can tell I'm having withdrawl symptoms.
The vibration I had was bad and getting worse. I could put the motor in neutral and coast down through the 70-65mph vibration speed and it would rattle the change in the ashtray. When we got back from our last trip out, it was enough to almost see the seats vibrate at 67mph. I crawled under it and could twist the shaft back and forth and get a healthy clunk out of the differential. The ring gear looked worn out at 44k. All the lovelies at the dealership could tell me is it's normal and they're unaware of any TSB in the works. I told them I'd pay for it if they'd just fix it. They looked at my like I just asked them to explain the theory of the gamma ray flux transducer.
I went to look at some '05s with the aluminum shaft and bandaid weights on the chassis. I can't take the chance after the '03. I definately can't go with a Dmax or PSD. So I'll burn some gas while Dodge figures out how to mate the mighty Cummins to the new Dodge truck. Then I'll see what's available in a year or two.
If you had the vibe, you would know it. You wouldn't have to wonder if that's it. My new Hemi resonates as much vibration from the 3" exhaust at 1750rpm as the Cummins does at 2100. You feel it more with the Cummins because the hydro boost hoses transmitt normal engine vibration straight into the firewall and everything that's bolted to it. That's normal. I can't relax when I know the driveshaft is under there hammering the life outa the tranny and rear end. Do the weights make the vibration go away or are they still there shortening the life of the driveline and we just can't feel it?
Withdrawl was bad when I quit smoking too...

hoot

What stinks is Dodge's refusal to fix the trucks. Vibration and death wobble forever.

Not everybody gets those problems but if you do, DC does not fix it. They simply brush you off so they don't get a trial fix against them towards the lemon law.

I had both. I minimized the vibe by going to larger tires. It's almost indescernable now. Dodge said in April they would get back with me on the fix. They said DC is working on it. I heard they have been telling customers this for over a year now.


Death wobble is a balance of tight parts and proper caster. Works for me. Had it once. DC is not addressing that issue either.

routerguy99

Fixed by these part numbers...
Part Numbers # 52853185ac
part number # 52105934ae

Drive Lines



https://www.dieseltruckresource.com/...threadid=52192

dosugly

Hey routerguy, whats up, the shaft numbers you list are for steels. Dealer istalled them and the vib actually seems a little worse. I absolutely hate this truck and I will not rest till the guilty party is brought to justice, I paid 40.000 dollars plus for a total piece of crap.

NJMurvin

Dosugly,

This is the info I'm getting as well. Sorry to hear that new shafts made it worse. My vibe is annoying, but not crippling. My dealer won't even log the problem because they're not allowed to test drive above 65mph.

Neil

kry226

I'd find another dealer.

cjjuckett

I have a 2000 2500 ext cab and I have the exact problem and was wondering if my front rotors are locking a little as they seem to get very hot. Hot enough to have the chrome bolt covers get pretty warm. I have this PENN Extn warranty that I am hoping will cover whatever the shop finds. I know that the Trac bar is gone and since I bought the truck recently and love the diesel, I a want to make it all right. My Drone noise also happens at a lower speed as well.

redarmyracer

try inflating the tires ALOT. go to MAX psi and see if that changes anything. This may help to find out if it is the tires.

bgott

I don't know if this will help y'all diagnose your vibration, but, I have a hell of a vibration between 70 and 75, worse at around 74. This only happens on one stretch of I- 10 near where I live. I can run it down I- 45 on the new pavement and it's as smooth as a baby's butt at all speeds. Could the vibration have something to do with the roads you are running on? This is on my '06 QC 4X4 longbed auto.

flamered

Just drove my 03 from OH to SC and back. Driving around OH with 65MPH limit, never noticed - but with the 70 in WV and NC, this truck just sucks between 70-75. Runs great and right about 70 it starts to vibrate - not really perceptible via steering wheel or via shifter, but rear-view mirror vibrates and cannot discern things in the mirror well. And every dang rattle in the dash and door are brought out by this. Odd thing is at 75 it goes away, as smooth or smoother than 65 and below. So I just drove 80. Not sure if it was any particular stretch of highway or not - too annoying to continue to drive at the speeds between 70 and 75 when it seems like the truck's dash and door will vibrate apart!

But here in OH not even sure where the dealer would be able to drive it. Guess I just have to live with it?

Have 3.73 gears, figure 4.11 would probably just move the vibration lower. bgott if you have 4.11 gears maybe that jives with the problem I have?

John Halter

First you need to find out were it is coming from and for me the best way to that was to put it up in the air and take it up to the speed that the problem occurs . I then went under neath and carefully laid my hand on the drive shaft and felt for the vibration and fixed it by using the balance instructions in the service manual . If the drive shaft is not the problem rotate tires and see if it changes location . While it is up in the air if the vibration disappears put it in 4x4 to spin front drive shaft to see if that is the problem . Hope this helps because I found the dealer useless in finding it for me .