How many with the vibes

[WStoops]

I'm sure this is not very scientific but I would like to hear how many of us are suffering from this specific vibration starting in the 60+ mph range and up through 70 mph. Please respond with the starting mph, does it go away as you go faster, is it accompanied by a drone and where can you feel it, steering wheel, pedals, floor, etc. I've been told by the dealer that it is around 10%. Thanks in advance for your feedback. Wayne

 

[RedRam401]

Not to change the intended purpose of this thread, but I think that it might be good to see what the equipment (QC vs SC, LB vs SB, 2X4 vs 4X4, 3. 73 vs 4. 10, LS vs Open, General vs Goodyear tires) is on each of the affected trucks.

Just to see if there is a common factor.

I actually wondered if anyone has had their tires high speed balanced to see if it could be a tire fault, seems I've seen everything checked but this in the threads.

I hope that you can find a solution to your problem.

 

[phloop]

I've had the tires rebalanced in the first attempt to fix the vibe's. It helped a little but not much. It is not a tire balance problem I believe as I just removed the spacers on the rear of my truck to lower it and that has helped the vibe problem more than the rebalance of the tires, makes me think its a drive train alignment issue. At least in my case.

 

[WStoops]

Not to change the intended purpose of this thread, but I think that it might be good to see what the equipment (QC vs SC, LB vs SB, 2X4 vs 4X4, 3. 73 vs 4. 10, LS vs Open, General vs Goodyear tires) is on each of the affected trucks.

Just to see if there is a common factor.

I actually wondered if anyone has had their tires high speed balanced to see if it could be a tire fault, seems I've seen everything checked but this in the threads.

I hope that you can find a solution to your problem.

The tire balance is the first thing I had done on my own. As a former service manager and tech, this just doesn't feel like a tire balance problem and is worse on accelleration or throttle application to maintain speed uphill. Balance made no difference. AFTER that I rotated the tires to make sure and it still made no difference. Pinion angle adjustment did change the onset speed somewhat but screwed up the alignment with a sharp pull to the right.

when they realigned it the vibration got worse and the onset speed went from 65 back to 60 mph. The fact that the pinion angle adjustment made a change would seem to indicate that it is in the front driveshaft. Something else going on there as well, IMHO. Like maybe engine, transmission mounts too stiff, exhaust system hangers too stiff or too soft maybe. Feels like the drive train and engine are mounted right to the frame. When it comes on it resonates through the whole vehicle.

 

[RedRam401]

Hmmmmm!!!! For grins I would be tempted to try running with the front driveshaft removed.

If that wasn't it then maybe try without the rear driveshaft.

 

[fj40tom]

If that wasn't it then maybe try without the rear driveshaft.

I would not recommend doing that. You do NOT want all of that power and torque running only to the front axle. Things will go boom.



Cheers,



tp

 

[BNH4221]

I have dealt extensively with the dealer and a DC tech regarding my 70 MPH vibration.

The DC tech told me that DC believes the vibration is a result of what they call a "Third Order" vibration. That is, engine vibration, driveline vibration and body harmonics all come together at a specific speed, in my case 70 MPH.

Accordingly, isolating that vibration is nearly impossible.

I removed the front shaft and the vibration was gone. The DC tech also spent about 6 hours indexing the front shaft and adjusting caster to alleviate the vibe. He was pretty much successful as it is barely noticeable (except to me).

We had a long discussion about the new American axle and DC's choice to have an axle that is continuously connected to the transfer case. It was a simple matter of $$; fewer parts and greater profit if you delete the axle disconnect. Of course, a continuously turning drive shaft and be a source of vibration.

Also the pinion angle on the AA is different than the old Dana. I believe it exits the pumpkin at a higher location causing a different, steeper angle. This can add to the vibration.

So, there are many and varied causes to the dreaded vibe. Will a new shaft cure it? Perhaps.

DC is allegedly experimenting with hanging weights off the body to dampen the vibe. Yeah, right.

The bottom line from the tech was basically live with it. DC is not really interested in pursuing a fix because so few people complain. Too many $$ for too few complaints.



Well, enough out of me.



Steve

 

[sag2]

Actually, most cars and trucks have weights hanging off of them to cancel out vibrations. Our trucks now have a weight on the PS hose, and it does make a difference. The Jeep Liiberty has a tuned set of weights hanging off the rear diff. We call them cow balls because they are so big. They are tuned to the frequency of the offending vibration and cancel them out. Most steering columns have a weight of some kind inside to cancel vibration, and finally, a few 1500 Ram's have a tuned weight on the rear of the frame to stop road vibration. They were in the process of writing a TSB that uses the weight.

The Cummins (and all other 6 cylinder engines) have a natural third order vibration. The drone or cyclical beat that you hear is when the normal third order and the first order drive line vibrations interact. You can't get rid of the third order, but you can balance the drive lines(s) to vibrate at a different first order frequency that does not get excited by the third order. Actually it is very complicated. A buddy I know in Detroit told me that the engineers took a bad 70 mph truck and dropped in a hemi. The vibration and drone were gone just by changing the engine to a V-8 that has a different natural frequency.

 

[LSteiner]

Sag2,



Pretty interesting post, thanks.



Larry

 

[Gunnernmybike]

Well, I had my front end aligned a couple of months ago by the dealer because my truck was dog tailing. On my work order it states they found the rear thrust angle was at 3 degrees and the front was toed in. They were able to get the back to 1 degree thrust angle and the front toe to 0 degrees.



Before I took it in, it drove fine other then the dog tailing. There was no vibration or drone. Now right at 70-73 mph, I have a drone that seems to pulsate (the pitch goes up and down).



I think its got to be the new angle of the front end alignment. I haven't taken it back yet but will shortly.



Check my signature for my truck specs.

 

[BNH4221]

Sag2 -



Makes sense to me. I was mostly repeating what the DC tech told me, rather, what I remember the DC tech telling me. Much is always lost in translation



Either way, wouldn't it be nice if DC acknowledged the problem and then actually tried to fix it?



I spent nearly 40 grand on a truck and DC wants to hang a set of cow balls on them to fix what I believe is an inherent design flaw? No thanks. Build it right the first time please!



On edit: If the solution to the problem was to hang a set of weights off the frame or axle or whatever, why has DC not yet done so? It has been 3 model years and they still have the issue. I think it is more design flaw than inherent vibration of the first, second, or third order.



Steve

 

[WStoops]

Sag2 -



Makes sense to me. I was mostly repeating what the DC tech told me, rather, what I remember the DC tech telling me. Much is always lost in translation



Either way, wouldn't it be nice if DC acknowledged the problem and then actually tried to fix it?



I spent nearly 40 grand on a truck and DC wants to hang a set of cow balls on them to fix what I believe is an inherent design flaw? No thanks. Build it right the first time please!



On edit: If the solution to the problem was to hang a set of weights off the frame or axle or whatever, why has DC not yet done so? It has been 3 model years and they still have the issue. I think it is more design flaw than inherent vibration of the first, second, or third order.



Steve

Hi Steve, I'm with you with respect to design flaw. My mechanical instincts tell me there is a higher number of vibration problems than we might think. Many are accepting of it as just being the way it is. I drove a new Ford Powerstroke yesterday and it is totally smooth at 60-70-75, which is as fast as I drove it. At idle it is slightly quieter than my 600 but on the highway it is quiet as can be and no vibes. Still, that is like comparing apples to whatever. According to the dealer, removal of the front drive shaft eliminates the vibration completely, a fact supported by the total lack of vibration reports on 2 wheel drive trucks. The fact that 2 wheel drive trucks are devoid of the vibration would indicate that cow balls, introduction of another vibration to cancel out this one, like noise reduction technology, is not a satisfactory solution.

And that third order vibration BS is also not logical when removal of the driveshaft cures the problem totally. I should add the caveat, "or so the dealer says", as I have not witnessed it myself. My lemon law hearing is scheduled for 2/24/ 05. I did opt for a replacement truck and will definitely drive it on the highway before I take anything.

 

[DJennings]

I have a vibration at about 70-75 mph that sounds similar. I also think it has something to do with the front driveshaft because I was driving ~60mph in 4wd and it was horrendous, especially under load going up hill. The vibration feels like it is definitely before the ring/pinion (not in wheels/tires) because of its high frequency. Front end was aligned two weeks ago after wheels/tires and 2" leveling kit were installed. I had not put it in 4wd when stock, so I have no reference to see if the 2" kit might have affected driveshaft angles. I really doubt 2" would cause this, but it would be nice to hear if someone with stock suspension is experiencing the same problem.

 

[sag2]

WStoops

You sound pretty mechanically minded. If your vibration goes away with the front shaft removed, you can easily try something to see if it makes it better. I'm betting you can, and it would be interesting to try it, even if your dealer won't.

Get a hose clamp and put it on the front shaft with the head of the clamp lined up with the factory weight (most have a weight) and drive it. Note better/worse using the old assometer. Next rotate the clamp 90 degrees, and evaluate. Go 90 more, then 90 more. If you find the best spot (and you may not) try adding a second clamp on the best spot and drive again.

Bring a nut driver and a piece of cardboard and you can go out on the freeway and do the whole test in 15 minutes assuming the off ramps aren't too far apart. If nothing else, you can make it better until you get another truck. If the clamp(s) fix it, the heads weigh about 14 grams, and you can weld the weights in place of the clamps. I finally purchased a gram scale, and can exactly weigh the clamps before I weld the final weight on.

I have had very good luck fixing them, especially if the vibration is front only.

 

[TPappas]

Has anyone tried an aftermarket driveline, like some of the serious off roaders use? I think one of the ones that comes to mind is High Angle Driveline. I have seen them advertised in the 4x4 mags.

 

[Summit]

i think its more so the 48re in odrive and second its the front shaft.

keep it in drive to redline and it s not noticable. mine vibes as soon as the torque converter locks. tech told me to buy aftermarket one as replacing with another d. c. one wont fix it.

 

[WStoops]

What about the standard shift 4 wheel drive trucks with the vibration? There seems to be a fair number of them. That and the fact that I have not been able to find any reports of 2 wd trucks with the same problem. personally, I think it is in the front drive shaft as it is short, has only one constant velocity joint, and the angle is off. There was a thread a few months ago about front manual locking hubs that were in the works. I'll do a search and see if we can resurrect that thread with some new info.

 

[WStoops]

I forgot to mention this piece of supporting evidence. The dealers all seem to do the same thing to solve the problem, in most cases unsuccessfully. They do the drive train realignment, pinion angle/caster adjustment to try to get the front shaft into better alignment. Essentially, misaligning the truck and creating a new problem to solve another one. Those who start replacing a lot of parts in the front end are missing the point, its not a defect in the sense that something is broken. It is in the engineering. I do wonder though why my 03 gasser was as smooth as can be. Wish I had some access to it to check the angles of the front shaft on that one.

 

[sag2]

It is not the angle (in most cases) that is causing the vibration. The vibrations are almost always first order which is balance. Angle problems are second order, and they are hardly ever seen on the Ram. Now on the other hand, the Liberty has first and second order vibrations, but the second order hardly ever cause a problem. I have found myself chasing second order on a Liberty, when a "good" one also shows some second order. Every vehicle is different, which does not make much sense, but it is the reality of what's out there. It's just like every Cummins seems to have it's own different noises.

If someone can post a photo for me, I have a shot of the vibration analyzer the dealers can buy that illustrates the different vibrations.

 

[claymike]

Had the vibration at speeds over 70 took it to the dealer and they replaced the front drive line. No more vibs.