junebug95628

Hello All,

I have a mid frequency vibration that I'm trying to locate. Any thoughts or experiences greatly appreciated.

Happens between 1600 and 1900 rpm. The greater torque output from the motor produces more intense of a vibration. IE in OD at 1700rpm pulling 10k trailer you can feel the vibration in your feet pretty good. Empty in 3rd accelerating on freeway you can barely hear it. Can't tell if it happens in 1st or 2nd as torque converter in not engaged at that speed and I cant get motor to work that hard geared that low. Beings it happens at same rpm verifiable in 2 gears I assume its not in anything past input shaft of tranny. (been proven wrong once before)

I have changed drive u joints, center bearing, and recently upgraded torque converter to Goerand. Vibration existent before and after these parts changed.

junebug95628

Spent last 2 hours reading tons of vibration posts and couldn't find much that resembled my condition. Most are u-joint related which is what I thought this was and I changed those and the center bearing last weekend. Unfortunately, the vibration continues.

Possibilities:
1- transfer case output bearing - don't think so because the vibration isn't speed determined but more RPM consistent
2 - harmonic balancer - could a bad HB only vibrate during times under heavy load?
3 - injectors or fuel supply - hmmmm don't know??
4 - input shaft bearings on trans - this would suck

This noise/vibration does indeed sound bearing related to me. It has worsened over the past year. I used to hear it vaguely under hard acceleration empty but then I recently moved my "new to me" 10k 5ver up the hill and the vibration is very evident pulling hills at 1600-1900 rpm with that load.

papaduck

It does sound like the harmonic balancer. The vibes will get worse under load. Check the rubber between the hub and outer steel ring and there are 2 timing marks that should be aligned. If it shows any deteration then it should be replaced. My maintenance manual says to check it every 30K.

I just changed mine and put on the viscous fluid damper for the Cummins 6.7L. Parts were about $300.

Hvytrkmech

Try shimming the carrier bearing down a bit. The drive line angle could be incorrect and under load it would amplify a problem.

Sur5er

Never hurts to check the damper:

DAMPER - CRANKSHAFT
REMOVAL
1. Remove the accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
2. Remove the four (4) damper to crankshaft bolts and remove damper and speed indicator ring.
INSPECTION
1. Inspect the damper hub for cracks and replace if
any are found.
2. Inspect the rubber member for deterioration or
missing segments.
3. Inspect the index lines (1) on the damper hub (2)
and the inertia member (3). If the lines are more
than 1.59 mm (1/16 in.) out of alignment, replace
the damper.
INSTALLATION
1. Install speed indicator ring.
NOTE: The speed indicator ring is located over a dowel pin.
2. Install the crankshaft damper and bolts. Tighten bolts to 40 N·m (30 ft. lbs.) torque, plus an additional 60°.
NOTE: The damper must be installed so the hole is located over the dowel pin.
3. Install the accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - INSTALLATION).
9 - 2684 ENGINE - 5.9L DIESEL - SERVICE INFORMATION DR

junebug95628

Hvytrkmech - hmmm- I do have air bags... do you think the engineers actually factored in squat with heavy loads to set the drive line angle?? second thought, the vibration is getting progressively worse.



How much runout is tolerable in the trasfercase rear output

junebug95628

@sur5er- Thank you for the manual pages, fortunately I do have a nice pdf file of the manual and the parts list.

junebug95628

update.

Checked the harmonic dampener and that is visually good. Made a 600 mile trip last weekend with 4 guys and all our gear. Moving down the highway at 70ish I can feel the vibration at my feet in overdrive. Back out of the throttle and the vibration lightens to almost undetectable. Coast and put it in neutral and it smooths right out. Worst is torque converter locked-up in OD.

Goerend and I have been talking about the one roller bearing in the transmission that receives a thrust load when in OD and no thrust load when OD is off. Interesting but wouldn't I then hear the vibration just as strong in OD whether or not the torque converter is locked?


The tech at the dealer thinks its an unsolvable issue in driveline, but he hasn't heard it yet.

I leave for a trip pulling 12k to Yellowstone in 2.5 weeks.

ramman

JMO u-joint or carrier bearing or even a motor mount,try cheap and easy first.

junebug95628

Ramman, those are the first things I did, no change.

junebug95628

Spent some time with the tech at Drive Line Service of Sacramento today, what a great outfit! Al took a ride with me pulling my small trailer and gave some input. We could get the vibration to occur in third and OD. This pretty much eliminates the roller bearing in the transmission that Goerend said could go bad in the OD section because that bearing only receives the side load in OD.

The vibration occurs at approx the same rpm with the torque converter locked up not at a single speed. Al from Drive Line firmly believes it is not in the drive line because it doesn't occurs at the same speeds but is torque and rpm based.

After some Internet searching I am back to the harmonic dampener. Reasons why are; vibration occurs at approx same rpm in different gears independent of speed. One thing pointed out to me is that the vibration is most prevalent when the torque converter is locked up. A torque converter is a big fluid dampener, right? So when it's not locked up it dampens vibrations, locked up it transfers all vibrations...?

Does that make sense?? I'm thinking a Fluidamper dampener might be the ticket, what do you think?

papaduck

If you decided to replace the harmonic damper then go with the fluid damper for the 6.7L. Parts at Cummins are just under $300. You will have to replace the fan pully and 4 bolts.

Damper p/n 4933224 ~$227
Fan Pulley p/n 4930580 ~$50
Bolts (4) p/n 4937228 ~$3 ea

junebug95628

wish I would have seen that 20 min ago... summit price matched the Fluidampr to $366 for me though so not too bad. hope this solves the issue...

thanks for posting the part numbers! I'm sure that will help out the next Joe!

papaduck

One good thing about what you are getting is you will not have to replace the fan pully which is the only hard part about using the 6.7L parts.

DodgeRam24V

can you hear your vibration or just feel it?

3 days ago i heard something under my 03 that matches you description at them rpm and speed. only around 50 MPH in OD.

i haven't crawled under it and took a peek yet, maybe I'll do that today.

Duck, is the pulley size is different for the fan, is it to change or will it change the fan RPM?

I'd like to speed mine up on the 99 to help keep it cool towing stuck in traffic in hot weather.