team222 Posted July 9, 2015 Share Posted July 9, 2015 2007 Dodge 3500 5.9 automatic, 4wd, 4.10. 90,000 miles, 1 prior owner Modifications: None, truck is stock Issue Any RPMs in top gear below 1900…. acceleration creates a vibration. At 1900 it goes away. This vibration can be felt in the drivers side floor and steering column. My wife says she can feel it also on the passenger side. There is no to little noise with this vibrations, but a very faint “growling” can be heard sometimes listening very closely Truck Usage We want to go out west fulltiming in our 5th wheel, unfortunately the departure has been delayed due to this issue and no one local including the Dodge dealer can diagnose or fix. We would be more happy to pay for help on this….and please accept this offer. Circumstances 1. I bought the truck early in 2014….no vibration 2. Turned out it needed a head gasket and also one cab bolt was broke and these were repaired. After these repairs the vibration started. 99% sure it was not there before. Action to Date 1. Driveshafts balanced. This reduced the vibration and sometimes there was no vibration, Now after 500 miles or so the vibration is back and same as it was prior 2. Carrier bearing not replaced during driveshaft balance, but acceptable per examination by the shop that specialized in driveshaft balancing. 3. U-joints expected and acceptable My Tests 1. Accelerated up to 80mph …..put into neutral ….no vibration on coast down at any speed 2. In second gear …accelerated from 1000rpm to 2500rpm …no vibration Thank you Mike South East PA Quote Link to comment Share on other sites More sharing options...
Megatron Posted July 9, 2015 Share Posted July 9, 2015 Hey Mike, Welcome to the 4WD Mechanix forums. Sorry the Ram is giving you fits. But like all issues, it can be fixed. As for your bad vibrations. These are one of the hardest things to help diagnose over the internet, well right behind noises. But I'm sure we can help you get some ideas out there on things to check. To start with your explanation and testing. You say in top gear below 1900rpms you have vibrations, but in any other gear at the same speed you have no vibrations? Or are you saying in second gear at the same rpm you have no vibrations? The same rpm in 2 different gears will not be the same rpm of the driveshaft. If it is still a post transfer case vibration its all about speed not rpm. Confirm for me that you tested different gears at the same mph not rpm. You would really need to get to the speed of the vibration and then down shift and maintain that speed and confirm if the vibration is present. It may be tricky to detect given the increased engine noise and vibrations, but this would eliminate all of the u-joints and shafts front or rear if it goes away. I have seen problems with front u-joints and mid support bearings (what you call the carrier bearing). As for your rear driveshaft balancing and mid support bearing inspection, I have often wondered when the balance a drive shaft if they do it under the matching torque of the engine and drivetrain load. If not, then there stands to be reason that a visual or at speed balancing may not reflect a mid support that is flexing under the big torque numbers of the modern diesel engine. I had similar vibrations you are referring to and mine turned out to be the mid support on the rear driveshaft. It looked fine and was stiff, but under big loads and certain mph it would vibrate under acceleration. Swapped in a one piece rear drive shaft and no more vibrations. My red flag on your testing is the fact after you did balance the shaft you had a period of no vibrations. This, to me, still says something in the rear shaft. It is possible one of the balance weights have come off the driveshaft. so give that an inspection. Now there are more complicated things that could be at play, but for now I say we stick with simple things for further diagnosis. Check the driveshaft for possible missing weights and see if you have a lot of play in the mid support bearing. Now, there should be some due to the rubber sleeve it rides in. This is to reduce any vibrations transmitting through the frame. I know you said your vehicle is stock but just double check the driveline angle. It needs to be as straight as possible going through the mid support bearing or it will induce vibrations. I have a big lift on my truck and it took about 4 attempts to shim this bearing up and down to get the vibrations tuned out of it. If your truck is sagging any on its springs you may have changed this angle and created some vibrations. Once you can confirm some of these things we can move onto transfer case issues and transmission vibrations, but to be honest I feel pretty good on finding it in the drive shaft. fingers crossed ha-ha Dustin Quote Link to comment Share on other sites More sharing options...
team222 Posted July 10, 2015 Author Share Posted July 10, 2015 Hello Dustin......thank you so much for your time and answer. My replies are as follows You said >>>> To start with your explanation and testing. You say in top gear below 1900rpms you have vibrations, but in any other gear at the same speed you have no vibrations? Or are you saying in second gear at the same rpm you have no vibrations? The same rpm in 2 different gears will not be the same rpm of the driveshaft. If it is still a post transfer case vibration its all about speed not rpm. Confirm for me that you tested different gears at the same mph not rpm. You would really need to get to the speed of the vibration and then down shift and maintain that speed and confirm if the vibration is present. It may be tricky to detect given the increased engine noise and vibrations, but this would eliminate all of the u-joints and shafts front or rear if it goes away. My reply >>>> Yes there are vibrations in high gear upon acceleration that stop at 1900rpm. I did try second gear all the way up from 1200rpm to say 2500 rpm and = no vibrations. This was all rpm based, not speed. I will try this as speed based tomorrow and post a reply. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> You said >>>> I have often wondered when the balance a drive shaft if they do it under the matching torque of the engine and drivetrain load. My reply >>>> Here in SE PA it seems there are only a few places that can balance driveshafts. I had the entire drive shaft assy front to back taken off because the company that does the balancing does not do this......the company that did this delivered it to the company for balancing and check out. I wanted was all new ujoints and carrier bearing replaced and everything balanced....this way it would eliminate 3 things right off, but this got lost in the translation What I got was the balance only. What I can do tomorrow or Monday is go over to the shop that did the balancing and find out what they actually did and get back to you. Plus, they can check to see if all the weights are still in place. All this brings up another matter in that I am not asking you to do this free.....infact I would like to reimburse you for helping. This way you could talk directly to this shop if need after I report back tomorrow and save time for both of us. Will get back on this to you after I talk to them >>>> Another phase 2 option is to go to a shop that has a stock truck like mine and have them swap out on a temporary test basis the entire drive line that from a truck that does not have the vibration mine does. I have a place that will do this. If this works ....maybe go right to a 1 piece driveshaft might be the right approach to get it done and solid once and for all? If they would have a truck that has a one piece driveshaft for a swap over swap that over instead ...skip the above..... and go right to installing a new one piece drive shaft.if this eliminates the vibration. Later now and thx for the steps in this path to get it fixed and done once and for all Mike Quote Link to comment Share on other sites More sharing options...
Megatron Posted July 10, 2015 Share Posted July 10, 2015 Hey mike, I think you can skip the one piece drive shaft. They are by no means cheap. Its 800$ alone for that. I think you will find it way more beneficial to stay with a stock style setup for your intended use. For strength there is nothing wrong with them, they just wear out like everything else does. Its really a bummer that the shop you hired didn't get your directions right the first time. This would have eliminated you questioning the components of the shaft. U-joints and bearings have a life span and the factory ones can not be serviced with grease for increased life. They are bound to fail. Mine went out at around 70K miles, but I have a lifted truck so that was to be expected. If I were you I would go back to the shop that did the work and tell them its worse after they touched it. They should own up to not getting the job done right the first time, like you had requested. I hate seeing people throw money at the same problem more than once. I mean a drive shaft with 90k miles on it a obviously needs rebuilt, not just balanced... That's on them for not suggesting it to begin with, not you. Balancing it at that point helped it from the wear it had already suffered, but that fix wasn't going to last long at all. http://www.driveshaftspecialist.com/Truckhtml/Dodge%20truck.html Here is where I got my driveshaft's done at. They may have a more stock configuration that's cheaper for your application. I'm not sure of your skill level at installing them on your own, but its really not that hard. I went with the 5" I piece aluminum, but I also double the factory output power and torque with my truck ha-ha. You really don't need all of that, but I know these guys build quality stuff and they ship pretty cheap. Let us know what you find out on the mph testing. Also, I don't always check this forum on the weekend so it may be Monday before I get your reply. Dustin Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted July 11, 2015 Administrators Share Posted July 11, 2015 Here's an interesting ditty about driveline balancing and rpm. I interviewed Dynotech Driveshaft Products in early 2013 at the SEMA-MPMC Media Trade Conference. Listen for the comment about driveshaft speed and balancing: http://www.4wdmechanix.com/SEMA-MPMC-Media-Trade-Conference-Dynotech-Driveshafts.html Dynotech Engineering Services manufactures custom driveshafts for street and racing applications. Hand built, computer welded and high speed balanced, these driveshafts have the best standards in the industry. For product insights and details on high performance driveshafts for trucks, SUV and Jeep vehicles, see the details. From the SEMA-MPMC Media Trade Conference, see the latest Dynotech Driveshaft products. Hear about the newest developments in driveshaft balancing. Quote Link to comment Share on other sites More sharing options...
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