[Diesel_Addicted_Dave]

Okay guys,

so many of us have dealt with vibrations that Accor around the 70 mph mark. While replacing many parts and blowing thousands of dollars on this problem with either none or minor improvements to the vibration.

I have heard Chrysler engineers know of this issue and can't figure out why some trucks do this. (normally don't vibrate when there new)

Anyone that had a vibration problem that managed to fix it please chime in and explain what you did to fix the problem. or what helped.

I know that the 2 piece drive shafts and simple u joint failures can be the common issues, but some of us still have an annoying vibration, thats even more brutal in 4x4 (i can't stand to drive my truck in 4x4 because it has the worst vibration and driveline noise) but still no visible signs of anything being wrong. all fluids and good u joints are good bearings are good. and its slowly getting worse over time




Here is what I have done to get some improvement at the 70mph range.

I changed my slip yoke out for a regular one with out a vibration damper and had the shaft rebalanced and u joints replaced. Changed my vibrations from around 70 mph to around 60... but still better over all but its still there. ( i can live with it in 2 wheel drive if its not hurting anything feels more like cummins harmonics in the 1600-1800 range. But with my dyna trac hubs locked in and in 4x4 its a brutal waaa waa waa sound. doesn't vibrate much worse with the hubs locked in and 2 wheel drive if at all... I know 4x4 does have vibrations but this vibration its NOT normal. its gotten worst over time.

SO anyone that has had this issue or still does have this issue please list out what you have changed and what actually made a difference see if we can get some common relations and try and pin point the problem down to a few variables

 

[Rpadar]

Are ur tires evenly worn. Within 3/32

 

[Rhinopkc]

If you remove the front driveshaft, does it go away? Have you always kept the front driveshaft greased? What is your caster set at?

 

[Diesel_Addicted_Dave]

Iv had 3 different sets of tires. it is not a tire issue. Not that kind of vibration. castor angles are stock. the truck used to be smooth sailing before I had the pinion side rear u joint go. once replaced its always had a slight vibration. was improved with a new slip yoke and re balanced shaft. The truck always had vibrations in 4x4. normal ones though you would expect. not as smooth as a 4th gen in 4x4 but always had vibrations present.
there just much worse. now. ams oil fluid in front diff rear has synthetic 140 in it.
control arms have never been touched. I installed a leveling kit my self with no change to vibrations. I had the rear axle wheel bearings tightened up because they where set a little loose from factory but no change in vibrations.

the front shaft rarely spins with my lockouts. had it rebuilt under 2 years ago, I do grease it once and a while though. I am going to try driving in 4x4 with the hubs unlocked to see if a vibration is enhanced since I haven't done that for a while,

 

[Diesel_Addicted_Dave]

transfer case fluid was changed 40-50 thousand km ago. still looks clean and fluid level is up.

 

[Diesel_Addicted_Dave]

thanks for the help though guys, excited to see how new goerend converter and billet flex plate effect things, Other plans are to try swaping rear drive shafts. gonna check runout on pinon yoke and maybe get front drive shaft balanced.

 

[dodge man2]

I have the same problem. I just put new tires on, no change. I also pulled my front drive shaft, no change.

 

[Rhinopkc]

Do you both have two piece rear drive shafts?

 

[dodge man2]

Mine is a quad cab short be. I think it's a one piece.

 

[cerberusiam]

Until you get rid of the flanged yoke on the rear of the DS and the differential you will never get rid of the vibrations. The flanged ends area consistent probem because they do NOT have a good center rim and they are almost always out of phase.

The second problem is the torsional harmonics just have set up vibes in the drive lines, the steel is the worst as it is almost perfectly attenuated to the wave harmonics. That big ugly damper is there for a reason, it helps but will not totally eliminate the problem. Removing just makes things worse.

Even the 1 piece DS is a problem with phasing on the flange and harmonics. The ends necked down to 4" cause most of the problems. Once you go to a full length 5" aluminum shaft and get rid of the flanged drive at the diff 99% of the problems are disappearing.

 

[1070]

I read somewere that we should mark the yokes and drive shaft before we take them out so they get put back the same way. it said they were balanced as a unit and had to be put back that way. I don't know if there is any truth to this or not.

 

[1070]

Until you get rid of the flanged yoke on the rear of the DS and the differential you will never get rid of the vibrations. The flanged ends area consistent probem because they do NOT have a good center rim and they are almost always out of phase.


ok that makes since years ago I put u joints in a old truck and put thiner clips in the caps, ( they were inside clips) it vibrated at about 50 mph but not any other speed. sort of the same thing you are talking about.

 

[Diesel_Addicted_Dave]

I would like to try an aluminum shaft one day. one from dodge drive shaft specialist but I wanna make sure im throwing 800 bucks in the right direction. How to I change out the flange on the rear diff? what would I replace it with? By removing my harmonic damper I lessened my vibrations. so maybe my damper was worn out and the rubber was cracked. Would be nice if someone made a fluid damper for the shaft.
and yes its a 1 piece steel shaft from factory

 

[Diesel_Addicted_Dave]

also some trucks came from factory without a harmonic damper. Im not sure why but not all of them did. maybe the ones that did had vibrations from factory so dodge put a damper on. doubt it but who knows.

 

[Diesel_Addicted_Dave]

I just wanna know why the 4th gens and even when all our 3rd gens where now had very little to no vibrations in 4x4 and of course smooth as silk in 2 wheel drive. Mine still has vibrations in 2 wheel drive around the 90 - 110 range but thats where the motor is torquing in OD. vibrations seem to subside when im making the same pull in 3rd gear. My other plan is to try a fluid damper but its not just from the engine.
in 4x4 its just terrible makes me wanna use 4x4 only when im slideing to the point where im sliding all over the road in the snow because 4x4 is not much fun in the higher highway speeds

 

[Diesel_Addicted_Dave]

cerberusiam did you have this issue once? and changed out the flange and shaft to correct the issue?

 

[cerberusiam]

cerberusiam did you have this issue once? and changed out the flange and shaft to correct the issue?

Yes, and still have the problem on 2 trucks. Both 05's, one and SB with steel driveline, and one LB with the 1 piece aluminum. Both are out of phase on the rear flange. You can tell that be just feeling the caps on the rear joint after driving for a while. Two of them are warmer that the others.

Mine is terrible from 1700-1800 roms and gets worse with load. Run it up to 1900 or and it smooths right out. My sons problem is from 60-65 after taking care with new ujoints and aligning the rear flange.

We are in the process of trying 2 fixes. Talking to Driveline Speciciaties and will be order a full 5" aluminum DS with standard ujoints instead of the one offs AAM uses, and, going to either a ubolt or strap on the rear diff.

Mine I am going to get the 4" ends for the better ujoints and bolt\strap rear connection to replace the flange.

Some type of viscous damper is going to help. Those wave harmonics start in the engine and wrok their way back. All the new trucks have a viscous damper on the engine and the other damper on the DS to try to mitigate the problem. Once you get some wear into them the problem still comes back though. You have to be SO careful installing u-joints as the alignment is critical. If you have to press too hard to get the joint out the ears bend and it throws it out of phase. That coupled with the possibility of misalignment on the flange and vibes are still possible.

The standard 1410\1480 ujoints and their associated parts are much more forgiving during installation and align much better when installed.

 

[Diesel_Addicted_Dave]

Thats very interesting, makes total sense though. my truck I bought it at 144,000 km I believe it had at leased 1 or maybe 2 u joint replacements in the past. I had to do a u joint at 160,000 but it was totally smooth sailing in 2 wheel drive before I had lock outs and in 4x4 it did have some vibrations but pretty normal for our generation nothing that would make you think something was wrong. so when 160,000 hit it started to vibrate really bad as a bad u joint would, me and my buddy did the replacement and we had a hel of a time getting the u joint out. I think the ears may have been bent. ever since then its never been perfect around the 70 mph / 110 range. and its been eating u joints every 20,000 km. the spicer ones seem to be lasting longer now though. But in 4x4 its a terrible vibration. like both the rear and front shafts are totally out of phase. and a very loud waa waa waa waa sound. So aluminum doesn't transmit sound as badly as steel?

another point to is every time i get my shaft back from the allignment shop it has a stiff point in the pinon side u joint (the one i changed myself a few years ago)
like the flange will still drop by its own weight but it still has a stiff point in the motion. I took it out the other day the stiff point seems to have gone but only in the range on motion the u joint would articulate. it is still if you move it past its normal range of motion

 

[Diesel_Addicted_Dave]

I also drove it in 4x4 with the hubs unlocked. and I couldnt really tell much difference. just the slight increase in vibrations that are so minor I can barley notice just as if my hubs where locked in in 2 wheel drive. but as soon as i lock them in and 4x4 I get some pretty good vibrations in 4x4 when the motor is torqueing in the lower rpms. and in the higher rpms (same speed but in 3rd) its a weird high speed vibration as if i was driving over very very fine road strips they lay on the edge of the road,

 

[cerberusiam]

The 5" is not as susceptible to the harmonics and the 1480 joints are a lot heavier. The driveline places claim the stock design is the problem, the necked down for 5 to 4".

Drive line specialties won't build a 4" drive line for the diesel, 5" only and the 1480 joints. Too many problems they claim with vibrations so a custom 5" shaft with 1480 ujoints is the solution. My son is ordering as as je can and if it works I will do one for mine.