2002 Dodge Diesel PU vibration at 60+ mph

HELP! I reallly need an answer to this. At about 125000 miles a slight vibration appeared and has progressively gotten worse. Now at 177000 it comes on at 60 mph and is pretty bad. I’ve replaced tires, shocks, hub bearings, u-joints and locator bars, all to no avail. The tires show no unusual wear and the drive shaft(s) u-joints appear good. I’m not the only one with this problem but Dodge denies any knowledge of it’s occurrence.

You need to describe the vibration better - especially where you feel it (e.g. in the steering wheel only, in the seat, the whole car etc), and anything that makes it change (e.g. is it just anything over 60mph; only on acceleration, deceleration, turning, braking, etc…)

Who has been checking it over & replacing the parts? Presumably a respectable shop has checked and double-checked basic things like ball joints & tie rod ends? Given tires a road force balance? Carefully checked the wheels themselves?

What kind of brakes do you have in the rear? Its not the most common cause of vibration, but one thing that can be at the root of elusive higher speed vibration problems is out of balance/out of round brake drums.

Someone should also have a look at the motor/transmission mounts.

Thanks for the response.
Vibration is felt all over, not just in steering wheel. It is heard as much as felt. it begins at about 60 under all conditions; originally began at about 70 but has progressively gotten worse. It is felt in the seat, floor and such. it is louder/more pronounced on the passenger side. In driving alongside the truck in my Avanti, there was no visible anomalies in the tire/wheel operation at speed (no wobble or bouncing).
I do my own mechanic work and have all my life but this has me stumped. There is no wobble in any axis on the front wheels when I had them off the ground to replace the hub bearing assemblies. I did the normal, applying pressure at the sides and top with the tire on to see if there was any movement; only verrrrry slight on fore/aft for the tie rods which I replaced with no effect. the only unusual thing was after replacing the u-joint and hub on the passenger side, there was a faint ‘clunk’ in the front end (seemed like in the pumpkin) when rotating the disk before putting the caliper back on.
The truck has disks front and rear. A local shop (Les Schwab) replaced/rebuilt the front brakes ~ 60,000 ago but there is no present indication of bad wear on the pads and the runout is well within limits (checked with dial indicator) and there is no indication of abnormal tire wear or cupping on the tires (they now have about 30k on them and have been rotated regularly); the rims were also checked for round/square ness by Les Schwab, (the same tire shop) the rear brake pads were replaced a bit later by yours truly and the emergency brake cable adjusted as the wifely person forgot to take off the e-brake one time. they were worn but not shot. The e-brake is internal in a small drum inside the disk brake assy but I had not considered them, thinking of larger causes for the vibration.
To my knowledge the motor/trans mounts have not been inspected but I will do so immediately. That has not been a situation in my experience so I didn’t check them. Usually a broken mount makes itself known in doubtless manner but I will check everything at this point.
thanks again
Chris

Chris,

I don’t see anything about the rear axle in your list of repairs. Have you verified the rear bearings are OK? They require pulling the half-shafts to get at, and aren’t exactly a fun job. If you jack the entire side of the vehicle (and put it on stands, yes) you may be able to pull one without losing much oil at all.

It sounds (to me) like there may be an axle bearing going, going, gone. Normally, I would think that would be present at most speeds above a crawl, but it’s worth checking into if you haven’t already. Having said that, if it’s only making noise when moving fast, a visual inspection may not be enough to tell you, anyway.

I assume (from the “I’ve replaced tires, shocks, hub bearings…”) line in your post that this is a 4X2. Yes? or is it a 4X4?

Chase

Thanks again, I really appreciate the help
It is a 4x4 2500 HO diesel with 6 speed manual.
I have not checked the rear bearings; hadn’t entered my mind because of no howling that they normally do. I did pull the covers and inspect the gears and tried to wiggle the pinon to evaluate the bearings but again, no indication of abnormality. I will check the rear wheel bearings as soon as I can, likely next weekend for the wifley person has Easter plans for me. LOL Similarly, i have not replaced the drive shaft u-joints because of no indication (pinging or looseness when trying to jiggle the drive shaft). I have closely inspected the drive shafts for loss of balance weight or obvious ding or bend that might cause an unbalanced condition - nada. I have not tried driving without the front shaft for the same reasons. As I said, I will inspect/replace/pray over the rear axle bearings next.
thanks again, and any other ideas will be greatly appreciated.
Chris

Since it’s a 4X4, you may be getting a little bit of “death wobble” due to a worn track bar and/or steering damper. To check the track bar for wear, look at it with the wheels on the ground while an assistant rocks the steering wheel between 9 o’clock and 3 o’clock, engine off. If there is any play at either end of the bar, replace it. If you can’t remember the last time the steering damper was replaced, replace it. They’re cheap.