I have a 2002 5.9 dually, within the past 6 months it has developed a high speed vibration, starting at about 60 MPH and increasing significantly after 70MPH. It feels as if it is coming up from under my drivers seat?? When I push in on the clutch it makes no difference..but below 60 it is barely noticeable..I just bought new tires, had them all balanced by spinning and then had them check it again w/o any remedy. The steering wheel is rock solid and it doesn't feel like it is coming from the front end..Any advice or analysis is appreciated. Doc

 

Move the back tires to the front and test drive again. If the steering wheel now shakes then clearly one of the tires now on the front have a separated cord or some other internal flaw. If this vibration just started after the new tires than that's where you have to start, as you have already done. Just keep working at it. Could be the tire tech missed a bad tire, could be a bent rim that was never an issue before. Depending on how co operative, or not, your tire shop is, you may have to take the truck and get a second opinion on the matter from a different tire shop?

Cheers and Happy Easter!

Mike

 

I noticed it before the new tires and balance, thought one of the rear tires had a worn defect....but I don't think so now. I was wondering about the universal joints?? I has 300k on it now...Could it be??

 

A failing u-joint can cause vibration, check for rusty colored dusting around the seals on each. A sure sign they are dried out.

 

Sorry, I misread your initial post. I thought that the vibration was a result of the new tire installation. I agree with Sixslug and his input about the u joints. Check drive shaft for obvious dent, missing weight (if there ever was one) etc.

Cheers!

Mike

 

What it is will depend on what kind of vibration you're talking about. A slow and wobbly vibration (tires) or a fast harmonic vibration (driveline).

You have an '02 which means you do not have the CAD front axle, so your front driveshaft is spinning full time. Not uncommon to have the front u-joints and double cardan joint to wear out on those non-CAD axles and start vibrating.

 

Replace the center support bearing.

 

As others have said, IF you have a 2002 without the center axle disconnect, that front shaft is spinning full time. If you want to somewhat verify it is the shaft, take out the front driveshaft and take it for a drive. If the vibration is gone, get that shaft to a reputable driveline shop for repairs.

If your truck is the no CAD variety, and with that shaft spinning all the time, this is nothing to play around with, we have had members have them come apart at 60 MPH and do grievous damage, of which they were very fortunate that it did not take their foot off or worse.

It really is that serious.

 

Fast harmonic for **** sure..the front end is rock solid, I feel nothing in the steering....the entire truck vibrates . I have to make a 2200 mile trip on May 1, would hate to drive that distance with that occurring. I sure do thank you for taking the time to help. Doc

 

This is a rear wheel drive truck lads, not a 4x4.....6 speed manual overdrive tranny....I love this truck...best vehicle I have ever owned!!

 

Do NOT drive this truck until you figure out the problem. If it is a u-joint then a couple thousand miles is only going to make the situation worse and you dont want to be that far from home and have to repair something. If you're truck isn't 4wd then you have one less thing to consider while looking for the culprit. If your truck is a long bed then you have two rear driveshafts separated by a carrier bearing. The carrier bearing can fail, causing slop which will vibrate, and again, it could just be a worn out u-joint. If you've never looked for a weak u-joint then what you have to do is get under the truck on level ground with it in neutral. Then forcefully tug, pull, wiggle, turn, jerk, on the drive shaft ends looking for ANY movement differences between the two yokes held together by the u-joint. This action also applies to investigating the carrier bearing. Also, as uncommon as it is, taking a look at the driveshaft for any hard scraps or dents could signify that the driveshaft was hit and is now bent. If you simply cant find anything which indicates a problem or worn out parts then you may have to take it to a driveline shop and ask for help.

 

Thanks for that excellent reply, and a thanks to all that contributed...I have an apt at the drive train shop on Wednesday but now I go there educated by you young men and I am indebted to you all. Doc

 

Glad to help!

 

Same here.

 

What did they find?