Unknown and inconsistent vibration

[caulk04]

So I have this ongoing vibration that I'm unable to find on my own, HALP! Sometimes it starts around 55, sometimes higher, sometimes nothing all the way to 80. I've not been able to pin down a point at which it starts or any certain bump/turn that starts it either.

The vibe is general, you feel it in the seat, console etc. It does not shake the wheel. I'm 100% sure it's not the tires, it existed before and after getting new tires and also after I added balance beads to all 4 tires. Shifting to lower gears does nothing. Accel, coast, or decel does not affect it. I've shifted into low range and ran through the gears (maybe 40mph) and did not feel any vibes so it seems not to be transmission. Front driveshaft has been removed with no effect. Rear driveshaft ujoints are all smooth with no slack. Sometimes it's pretty light, others it's bad enough that I can just watch in my mirror to see the bed shake slightly in relation to the cab.

I've driven enough junk vehicles to know what various terrible suspension components feel/sound like, that is not the case here. I replaced the lower links on the rear axle as two of those bushing were slightly suspect; no effect.

The truck is a slightly odd bird being a 149" WB 1500. Hoping someone has fought this before and has a silver bullet for it.

 

[crackerjack1957]

Sounds like you have pretty much covered it all.........if vibration in the rear only thing I can think of is driveshaft not balanced or axle shaft in the rear end.
Don't really know the history on vehicle so can't say for sure.

 

[Daw14]

Carrier bearings good?

 

[Wild one]

Is it a 2 piece driveshaft ,wonder if it could be a bad steady/center bearing

 

[tidefan1967]

Pinion angle slightly off maybe?

 

[caulk04]

One piece drive shaft.

Nothing has happened to the truck for the pinion angle to be wrong, though I suppose I could check it sometime.

 

[crackerjack1957]

Mileage when it started or when vibration started?

 

[mdc1990zr1]

So I have this ongoing vibration that I'm unable to find on my own, HALP! Sometimes it starts around 55, sometimes higher, sometimes nothing all the way to 80. I've not been able to pin down a point at which it starts or any certain bump/turn that starts it either.

The vibe is general, you feel it in the seat, console etc. It does not shake the wheel. I'm 100% sure it's not the tires, it existed before and after getting new tires and also after I added balance beads to all 4 tires. Shifting to lower gears does nothing. Accel, coast, or decel does not affect it. I've shifted into low range and ran through the gears (maybe 40mph) and did not feel any vibes so it seems not to be transmission. Front driveshaft has been removed with no effect. Rear driveshaft ujoints are all smooth with no slack. Sometimes it's pretty light, others it's bad enough that I can just watch in my mirror to see the bed shake slightly in relation to the cab.

I've driven enough junk vehicles to know what various terrible suspension components feel/sound like, that is not the case here. I replaced the lower links on the rear axle as two of those bushing were slightly suspect; no effect.

The truck is a slightly odd bird being a 149" WB 1500. Hoping someone has fought this before and has a silver bullet for it.

I always try to get American made whenever possible. When I couldn't get American made Goodyear or Firestone tires for my 3500 truck, the supposed tire guru at The Tire Rack steered me to this great Kuhmo tire. Short on options, I reluctantly ordered a set of four. These tires didn't last two years before the two rear tires exploded a day apart from each other. In the interim, I also chased a mysterious vibration. Tires were remounted and rebalanced by everyone I took them too. A few alignments were done, rotations, even a rear driveshaft was done. Nothing solved the vibration. One summer day while passing the Philadelphia Airport, one rear tire separated and I put on a spare. The very next day, the other rear tire exploded. On with the other spare. I have extra wheels and tires and some dedicated winter tires for the 2WD trucks. Low and behold, no more vibration. I saved the old tires for warranty purposes. The Kuhmos must have had internal tread separation that could not be detected or balanced out. I called The Tire Rack and they could care less. Not satisfied, I left a scathing review that they never posted. Buyer beware when dealing with The Tire Rack.

 

[670hoth]

It's wear on the splines of the front CV shafts.

 

[caulk04]

It's been doing it for a long time, since maybe 40k. There's just shy of 80 on it now. I think it's getting worse.

Front CV's...hmm. I hadn't really considered that. Once upon a time I had an 02 Dakota that wore the intermediate shafts and CV's to the point that they just spun. Maybe I'll take a couple hours one day and pull the shafts out to see if there's any change.

Can anyone confirm that the CV stubs are not needed in the wheel bearings and you can drive without them?