driveline vibration

[gump]

i have been chassing a vibration on my 99 d 5.9 for months have tried varios rim and wheel combinations have tried replacing bearings frt and rear checked all shafts for balance and run out , ring gear run out and tooth mesh is fine pinion nut is tight this always hapens at highway speed more so when its warmer out always at around 115 kms hr this is one nasty vib dirveline angle is fine drive shaft has been replaced its always in the seat of your pants this vib is awful. has anyone had an unexplaineble vib to give me some insight.
p.s this vehicle has never hit anything ive talked to chrysler engenering as i'm a parts mngr at a chrysler store they have know idea
rear axle is a chrysler 9.25 ratio 3.55 anti spin

[jeepfreek]

If its in the seat of your pants its more than likely in the rear of the truck. Try swapping the tires front to back and see if it transfers into the steering wheel. If not, then I would go after U joints possibly. Have the drive shafts been balanced?

[gump]

the tires ive tried are off of new vehicles never seen the road before vibration stays the same ujoints at first were replaced then i installed a new drive shaft still the same vibration then i indexed the shaft 180 deg. still the same i even tried the old hose clamps trick still no change i am at a loss
keep giving me ideas thanx

[jeepfreek]

Well indexing the driveshaft was going to be my next idea. Could it be possible that a drum is warped bad enough to cause it? I'm just trying to think of something that you have overlooked but sounds like your covering everything pretty well. It has to be something rotating so thats why I suggest possibly a drum?

[Ripped]

A tough one, it sounds like you have done everything already, wheel bearings axle bearings u joints, driveshaft

Consider taking it to a transmission or differential specialty shop, explain what you've done, and have them take it for a drive around the block... get some different advice

I had a mild vibration on mine, but it was entirely the stock tires, and switching / rotating them front- back made the problem more/less apparent

I am thinking a bearing in the transfer case... or a bent flange on a rear axle

Is it possible to have someone follow you in a another car on the highway, and have a look at the D when you are experincing the vibration, to observe if there is anything physical on the outside of the vehicle moving around

check your brake compnentry carefully ie warped rotor, brake drums are also balanced, perhaps a weight falling off would cause a small vibration

If it were an engine problem, such as a spun bearing, then you would be able to find it by just bringing the engine up to rpm.

If you stall the converter, do you get any vibration?

[jpi99]

I've got the exact same problem and its on highway speeds only and it gets wicked at times. I even got new rear tires and it still does it, seem like it comes and goes. You can watch the steering jump up and down its so bad. I am thinking its a shock, wheel bearings or I have warped a rotor. I'm swapping those out once I get my lift on.

[gump]

now ive tried it all checked rear axle flange runout there isnt any looked at engine mounts there fine just got back from the cottage kid has a chiped tooth from this vibration i just think a brick on the gas pedal and watch it go over a cliff will fix the problem just kidding i have our tranny guy deep in thought thinking its mabye something to do with the torque converter please keep the ideas coming in

[jeepfreek]

Is it only under acceleration or constant driving? Does it go away when you let off the gas?

[RPMLaabs]

Well, it's been over a month. DID you get it fixed, and what was it, or is it still vibrating? I would suggest putting it on a dyno if you have one available, it will either be apparent, or rule out the drivetrain and rear end and point you to the front end. Otherwise, it may just be the wind buffeting upon reentry.

[gump]

sold the truck bought a 300 m speacial i just got fed up with the thing,the worst thing of all is that i work in a chrysler dealership and the support from chrysler on this matter
was the worst that ive ever seen.