Vibration from hell!!

[RSchwarzli]

The mega is the smoothest truck dad has ever owned. Then something happened.



Went to dealer as the pinion seal was leaking. They also found an axle seal leaking. So they pulled both axle shafts, put in new seals, new pinion seal, and we drove home. Bad vibration in your butt on the seat included.



Went back the next day. What the heck did you do!?



We went under the truck on hoist with them (the tech we have known for years). Walked back through everything they did. Checked pinion yoke with dial indicator. All good. Checked tires. Good. Flipped driveshaft 180 deg even though it was maked and put on back how it was (was hung from the T case side and never disconnected). Drove home.



Bad vibration.



Went back. Tires were blamed. Rebalanced. One bad tire possibly. Replaced the one tire. Still there. Replaced a second tire. Must be U joint. Replaced U joints on rear driveshaft. Went for drive. Still there. Pulled front driveshaft off. Went for drive. Still there. Must be driveshaft. Sent out for balancing. Reinstall. HORRIBLE! Sent it to another shop. So far out they could not balance it. #@$%! at first shop. Dealer orders complete new shaft from Dodge with U joints.



Installed and went for drive. Still there. Replaced 2 more tires! Still there!!! Rechecked balance on all tires with a road force balancer. All looks good.



What the heck!?



The vibration is NOT rpm based but gets worse the faster you go. The vibration is not as bad as it was, but is still bad enough it drives you nuts! Vibration is felt badly at 35 through 45 mph and then gets bad again around 55-75.



Any thoughts? Front end U joints, ball joints, steering stabilizer and box, all done back in the spring. All else is stock on a 70K mile truck.



Please help! :{ I am open to any thoughts at this point. my father is a very unhappy camper at the moment and claims he is too old for this type of stuff! :-laf So it is now in my hands.



Where do I start looking? I am thinking trans back as it is not RPM based.



Robert

 

[KLauber]

No idea from down here as it sounds like you checked and re-checked everything. SOmebody will think of something... ... the beauty of this club!

Ken

 

[RSchwarzli]

Ken,



That is so the truth! I think I have checked more or less everything. Maybe some Yoda knows everything will point out the error in my thoughts! :-laf

 

[TBartlett1]

Does the truck shake like tire ballance?

Or does it feel like a higher frequency like perhaps driveshaft?

The fact that it was smooth before the pinion & wheel seals were replaced point to the driveshaft or pinion flange. Check to see if any weights were knocked of the driveshaft.

Can you feel any looseness in the pinion flange with the transmission in neutral it's possible the pinion is not properly preloaded allowing runout due to a loose bearing.

Is it a 2pc driveshaft? Are the u-joints lined up properly. All the yokes in the driveshaft should be in line.

 

[GaryCarter]

Put it up on a lift that raises by the axle tubes so the suspension is in the normal state of compression, but the wheels hang free. Get in and drive while someone goes under and finds the vibration source.



Good luck. These type of issues can be a pain to track down.

 

[EricBu12]

a head scratcher that is. . I vote for a pinion shaft out of alignment. if all other things are good.

 

[MChrist]

Carrier bearing, if a mega has one???

 

[AMerrill]

I would have to say look at the axles and the bearings because that is the only thing that you did not mention good luck on finding it

 

[Nyoest]

I'm thinking a pinion or pinion bearing problem. Prolly was a little loose before and now that it's tight it's showing up.

Put it on jack stands or better yet a lift and run it through the problem speeds.

 

[ata]

On the AAM pinion there is a crush sleeve between the bearings. This sleeve sets the preload on the bearings. When you tighten the pinion nut this sleeve starts to compress until the bearings touch the races. Then you turn it ever so little and check the preload with an inch pound torque wrench until the proper load is reached. What happened is the guy that changed the seal did was over compress the crush sleeve putting to much preload on the bearings and now you have a problem. They will have to replace the crush sleeve and reset the preload. That's what I hate about the AAM axles. But it's cheaper and takes less time to set them up. It's the only thing left.

 

[seafish]

Bschwarzli, as you must well already know, the successful completeion of EACH of the original repairs that your dad had done on his truck (pinion ring seal AND axle shaft seal) requires an experienced mechanic with BOTH knowledge AND patience , either one of which is, more often then not, in short supply at ANY dealership service center.



Since you have already eliminated most all of the other possibilities (tires, driveshaft alignment, driveshaft, AND u-joints), that MIGHT be causing a vibration that did NOT exist BEFORE the repair, I would venture that the vibration was caused by a slight mishap in the original repairs. It could be a bad part right out of the box, or more likely, as others have suggested, something gone wrong with the pinion ring seal/crush nut install and/or the axle shaft seal/shaft reinsatalltion.



Just my . 02...



PS--DO hope that your dad is NOT paying for all the parts that the dealership is throwing on his truck!!!

 

[RSchwarzli]

Does the truck shake like tire ballance?

Or does it feel like a higher frequency like perhaps driveshaft?

The fact that it was smooth before the pinion & wheel seals were replaced point to the driveshaft or pinion flange. Check to see if any weights were knocked of the driveshaft.

Can you feel any looseness in the pinion flange with the transmission in neutral it's possible the pinion is not properly preloaded allowing runout due to a loose bearing.

Is it a 2pc driveshaft? Are the u-joints lined up properly. All the yokes in the driveshaft should be in line.

Not tire. Frequency is too high. And with them all having been replaced... .



No. Single driveshaft. I believe only the G56s came with the 2 piece.



Yes. All U joints are good and lined up.

Put it up on a lift that raises by the axle tubes so the suspension is in the normal state of compression, but the wheels hang free. Get in and drive while someone goes under and finds the vibration source.



Good luck. These type of issues can be a pain to track down.

Yes, pain is right!



Will try this.

Carrier bearing, if a mega has one???

Not on this one... . Good thought though!

I would have to say look at the axles and the bearings because that is the only thing that you did not mention good luck on finding it

Yeah... I have a bad feeling it is looking more like that...

On the AAM pinion there is a crush sleeve between the bearings. This sleeve sets the preload on the bearings. When you tighten the pinion nut this sleeve starts to compress until the bearings touch the races. Then you turn it ever so little and check the preload with an inch pound torque wrench until the proper load is reached. What happened is the guy that changed the seal did was over compress the crush sleeve putting to much preload on the bearings and now you have a problem. They will have to replace the crush sleeve and reset the preload. That's what I hate about the AAM axles. But it's cheaper and takes less time to set them up. It's the only thing left.

Hmmm. Will have to look more into this. Sounds possible.

Bschwarzli, as you must well already know, the successful completeion of EACH of the original repairs that your dad had done on his truck (pinion ring seal AND axle shaft seal) requires an experienced mechanic with BOTH knowledge AND patience , either one of which is, more often then not, in short supply at ANY dealership service center.



Since you have already eliminated most all of the other possibilities (tires, driveshaft alignment, driveshaft, AND u-joints), that MIGHT be causing a vibration that did NOT exist BEFORE the repair, I would venture that the vibration was caused by a slight mishap in the original repairs. It could be a bad part right out of the box, or more likely, as others have suggested, something gone wrong with the pinion ring seal/crush nut install and/or the axle shaft seal/shaft reinsatalltion.



Just my . 02...



PS--DO hope that your dad is NOT paying for all the parts that the dealership is throwing on his truck!!!

I would have to agree. Logic still points to the repairs. So it says something in the rear housing.



No, the dealer has covered many of the parts...









OK. So all opinions are basically in the diff. Guess thats the next spot to look. As it feels like a up and down motion and sometimes side to side in ones seat, I would have to say pinion. As they were working on the pinion that makes sense. And if there is a faulty or incorrectly worked on crush sleeve... . Hmmm.

 

[GCroyle]

Didn't somebody post about a vibration or balance analizing machine that a dealer can setup and test drive with? I'm pretty sure someone had the name of said super gizmo recently.



Good luck,

 

[rscurtis]

I wonder if they dropped or damaged your driveshaft. A friend and forum member bought the one piece shaft and it was OK up to 65 MPH, and the truck was not driveable above that speed. It was high-speed balanced 3X and was better, but now the vibes are back at a little over 70. He had his original two piece shaft balanced by the same outfit and reinstalled it, it runs smooth as glass now.

 

[WCPoe]

I thought someone just posted a similar situation and all they did was to take the driveshaft loose at the differential end and rotate it 180 degrees, re-secure it and the problem was solved .

 

[NIsaacs]

I thought someone just posted a similar situation and all they did was to take the driveshaft loose at the differential end and rotate it 180 degrees, re-secure it and the problem was solved .

The OP already did that. I would pull the axles and re-check wheel bearing pre-load. Maybe one didn't get fully seated and is now loose as a goose. Are the axles the same length on an AAM?



Nick

 

[JFought]

NI yes but that was a pretty new truck 2011 ish
and had like 10K or less
his vibration was little to slightly mild, but tolerable

He did it out of curiosity, and it did make a difference for him.

 

[Mhannink]

no question in my mind its something in the diff that the mech touched while repairing. crush sleeve is my first suspect.



someone mentioned axle bearings. maybe i read it wrong but was it an axle seal leak or an wheel seal leak? big difference between the two. axle flange gasket would be quick and easy, and would not cause a problem. wheel seal leak is more complicated and could be done wrong.



i would put money down that if you keep driving it, what ever part is causing the problem will take out the seal, and that will be where the problem is at. who knows what else will fail to do secondary damage though. i say go back to the dealer and have them redo both repairs. if that solves the problem than they can pay for everything even the things you have payed for already.

 

[SRay]

Hello Bschwarzli, how's the rear end coming? Is it fixed? My dana 70 was the source of the vibration due to pinion coming loose. Even put back to specs, it was shot and needed to be changed over to the dana 80 before the Cummins trip. #@$%! I think the pinion being loose ruined the gears and the metal pieces everywhere in the oil ruined the bearings too. AND that was the shop's fault. #@$%!



For all those reading this: That dana 70 was rebuilt by 2 different shops 6 months apart at a total cost of $4000. Then I bought the truck, I was shown the reciept that the dana 70 is rebuilt. 2 1/2 years later since the rebuild, the pinion nut came loose. when I tried tightening back up, I found that I could not get the nut torqued to 220 ft/lbs as the pinion couldn't move anymore. It was jammed tight which tells me there are no shims inside for proper preload. #@$%!



Since then I've lost all faith in any shop working on my truck. I know there are good shops out there, but there are more crappy places than there are good ones nowadays.



Bschwarzli even found shops giving stupid or incorrect tech advice on sites like Cumminsforum as an example. #@$%!

 

[Mhannink]

Hello Bschwarzli, how's the rear end coming? Is it fixed? My dana 70 was the source of the vibration due to pinion coming loose. Even put back to specs, it was shot and needed to be changed over to the dana 80 before the Cummins trip. #@$%! I think the pinion being loose ruined the gears and the metal pieces everywhere in the oil ruined the bearings too. AND that was the shop's fault. #@$%!



For all those reading this: That dana 70 was rebuilt by 2 different shops 6 months apart at a total cost of $4000. Then I bought the truck, I was shown the reciept that the dana 70 is rebuilt. 2 1/2 years later since the rebuild, the pinion nut came loose. when I tried tightening back up, I found that I could not get the nut torqued to 220 ft/lbs as the pinion couldn't move anymore. It was jammed tight which tells me there are no shims inside for proper preload. #@$%!



Since then I've lost all faith in any shop working on my truck. I know there are good shops out there, but there are more crappy places than there are good ones nowadays.



Bschwarzli even found shops giving stupid or incorrect tech advice on sites like Cumminsforum as an example. #@$%!

here here, there is absolutely no one that is allowed to touch my truck other than me. ive worked as a mech in several shops and have talked to many who have had horror stories with different shops. plus my own experience with company trucks and the like have not been good. so my truck will never see the inside of a shop except for tires, and even then i watch them and make sure they are doing it correctly.



you are right there are some good shops out there. i like many of the ones i found through here, it seems that the performance shops and stay small and do well are very knowledgeable and have great care for their customers. i have one just around the corner from my house. its not a diesel shop, its a trans shop. the owner has been building transmissions for eons and many behind pull tractors and hot rods. he only does autos and all of trans have almost no problems. he is the only shop i will let touch my truck, course i have a manual now so he wont work on it, but my autos he did and they were good transmissions.