Mild Vibration when coasting at 60mph

[tschidas]

I have an intermittent vibration coming from what seems to be the front of the truck, it only occurs at 60mph, only when letting off the pedal and it doesn't occur all the time. Coincidently, it's now noticable after replacing front u and ball joints, guess it could have been there before, but the slop in the u-joints may not have allowed it to transfer? In any case while still slightly skeptical, I'm confident of the front end work done, new joints, etc. I've removed the front drive shaft and it's still there, checked the rear shaft and joints, etc. It doesn't seem to occur if in 4 wheel drive, but obviously I don't drive in 4 wheel at 60mph much. Again it only happens when letting off the pedal thus w/ no torque on the front drive line? Because of this it shouldn't be tire vibration which were rotated at the same time as the front end work? Its done it now for a couple months, hasn't gotten worse, but I'm at a loss and looking for any ideas or anyone else who may have experienced the same thing.

 

[TimothyLong]

Without knowing anything about your truck, there are a few things that come to mind. First, and this is a bit obvious, is tire balance. Did you have the tires balanced when you had them rotated? I have mine done every time they get rotated. Second, quite possibly your steering damper/stabilizer may be failing or failed. The stock one that Dodge puts on is pretty worthless. I know some folks who had a little vibration that went away after they replaced the steering damper. Third, there was a TSB, TSB 19-008-03, for vibration that could be felt in the brake pedal and steering wheel at highway speeds. It had something to do with the way the power steering pump would pulse. The fix was to replace the hoses going to and from the power steering pump with larger ones that dampened the pulsing. I had it done to my '03 (after going a few rounds with the dealer about it). Made a big difference. just a few things that I can think of right off.

 

[steved]

Sounds like a seizing universal joint...

 

[TAbbott]

I second the u-joint analysis. Vibrations that come and go with torque loading and float or negative torque (coasting against cmpression) at constant speeds are almost always drive line related. Joints, yokes, even bearings in transmissions and differentials can cause them, but the most common culprit is the u-joint itself.

 

[MMeier]

I have an intermittent vibration coming from what seems to be the front of the truck, it only occurs at 60mph, only when letting off the pedal and it doesn't occur all the time. Coincidently, it's now noticable after replacing front u and ball joints, guess it could have been there before, but the slop in the u-joints may not have allowed it to transfer? In any case while still slightly skeptical, I'm confident of the front end work done, new joints, etc. I've removed the front drive shaft and it's still there, checked the rear shaft and joints, etc. It doesn't seem to occur if in 4 wheel drive, but obviously I don't drive in 4 wheel at 60mph much. Again it only happens when letting off the pedal thus w/ no torque on the front drive line? Because of this it shouldn't be tire vibration which were rotated at the same time as the front end work? Its done it now for a couple months, hasn't gotten worse, but I'm at a loss and looking for any ideas or anyone else who may have experienced the same thing.

Did they do the axle u joints up front also, or just the ones on the driveshaft??

 

[mtnram]

I triple the driveshaft u joint or cv joint (up front). Axle wrap relaxes while coasting changing pinion angle which is critical in keeping the joint angles in phase.

 

[tschidas]

Just thought I would post an update to my outpdated posting, I recently finished installing DynaTrac Free-Spin locking hub upgrade on my truck, thus replacing the hubs, outer axis's, etc. including re-installing the exisiting u-joints previously installed, in any case I'm happy to say the vibration I had been experiencing is now gone whether the hubs are locked or free thus a great relief. Still not certain what the root cause was, but suspect the right side u-joint was possibly contributing. Now I'll feel comfortable driving my truck for 11 months out of the year w/o the front drive train spinning needlessly!