It has taken six months, ten service trips and countless hours on the phone with Dodge , American Axle and different dealers but heres what has taken the vibration away at expressway speeds.
Its the very first thing I told them when I took it in for the first time. The transfer case. I have had four rear driveshafts in, one front shaft and a new rear ring, pinion, bearings and now the transfer case. This has taken the vibration out about 95%. There still is a slight vibration when you are under throttle till you reach your maitained highway speed then it subsides. This I believe is still the rear driveshaft but when they come out with a larger dampner on the shaft I think it will be gone also. If you can move the dampner on the driveshaft (where it slips on to the transfer case tailshaft ) up about a 1/8 to a 1/4 inch by hitting it with your palm of your hand its too sloppy. This is the second truck this engineer has replaced the transfer case on and on both trucks it has solved the vibration. It took a lot of complaining at the dealer level before the Dodge engineer got invloved. But now Im almost vibration free and this truck is great.

 

I came to about the same conclusion last night. I had taken out front drive shaft with no change. Last night took out rear shaft and drove with no change so it has to be in motor, transmission, or transfer case. The damper on the driveshaft is loose I thought I could peel it off with my bare hands. I did notice that the outer rubber seal in the transfer case was cracked all the way around which I thought was odd but probably could happen if something is shaking. It looks like there have been a couple of people recently that had the transfer case replaced and fixed the problem. My problem has been getting someone to acknowledge that it has a vibration. Did yours have a Pulsating vibration that you could feel in the shifter, steering wheel, and accelerator like a gear had a tooth missing. Man I would love to get this fixed. Don't have the engineers name or number by chance? Its good to hear a few trucks are getting fixed at least.

 

how did you drive the truck with no rear driveshaft ...
front axle i know, but how did you keep the fluid in the transfer case

 

As much as I dislike this truck I was tempted to just run it that way but decided I would probably end up screwing myself. So I got a plastic sour cream container and taped it over the output shaft with black electrical tape, it didn't leak a drop in the 30 miles I drove. Seems like a pretty pathetic way to have to diagnose a problem on a new truck but it worked. When I took it off there was probably 1/8 cup of fluid that was in the cup. Anyone know if the transfer case fluid looks and smells like burnt transmission fluid? I wish i could figure out a way to remove the transfer case and take it for a drive but I believe that would be a little more trouble.

 

If you set the cruise and don't touch the accel. pedal does it seem smooth? Are you feeling it through the whole truck or just through the shifter and pedals?

 

Dosen't matter much if cruise is on or off but does seem to get worse on hard acceleration. Mostly feel it through steering wheel and shifter but in pedals sometimes. It normally does not shake the whole truck but seems at times it get at a certain frequency between truck, road, and speed that it does shake the entire truck. I wish it shook worse then I could get it fixed without hearing how this is normal. Someone at Dodge needs to pull their head out.

 

I can't get a dealership to even attempt a diagnosis. The best I've gotten so far is they took it on a test drive and acknowedged it. They just tell me it's "in work" by Chrysler.

 

Hoot your still one up on me I can't even get them to acknowledge mine. And if anyone checks the old posts something has been " in the works" for quite a while. Hoot is your vibration kind of a rythmic thump that is in the steering wheel and pedals, seats, etc. or different?

 

I have the same vibration. It's a rhythmic vibration from 1650 RPM to 1800 RPM. I only feel it in top gear and only while I’m giving it power. It's worse the more power I give it. Interestingly enough it's not very noticeable when my truck is at stock height, but when I have the 2" rear blocks in, it's there. I checked the angle of the u-joints and they are a bit out of phase so I shimmed the carrier bearing 1/4" with no relief. My next step is to shim the rear axle 2 to 3 degrees. We'll see what happens. I agree with the above statement that its some kind of combination of factors. Drive line angle/tight or bad u joint/tires/etc. I just wish I knew what it is so I can fix it!

 

So I wonder if there are any 2wd trucks with the highway vib. problem?

My tranfer case was replaced last friday. (not vibration related) This one is smooth as the the 1st one was. (Up to 95 mph anyway ) I just mention this to expose a possible quality problem in the x-fer case.
db

 

Well I removed the shim and unbolted the rear drive shaft from the pinion and checked for a tight u joint. No u joint problem. One of the recommendations in the service manual is to unbolt the drive shaft and turn it 180 degrees and try it that way, so I did. Basically between removing the shim I had put in and spinning the drive shaft, the vibration is now worse! My tranfer case output shaft does have some vertical play in it, maybe I'll have it replaced. I hate letting the dealer screw with the truck. It always has other issues after I get it back. I'm not sure what I'm going to do next.

 

Heres a little info on my 96 12V 330h/800+ lbs 4wd: Been fighting a vib for 3 months that started mildly then became a horrible shake at 35-40 and 65-70 mph. First I had the rear shaft joints & carrier replaced-still shook. Then I proceeded to change tires, wheels, shocks-still shook. Installed a BD heavy duty flywheel thinking the stocker was cracked-it wasn't & still shook. Put in new front ball joints, upper & lower and new brake rotors (this was a reach but was running out of options) still shook. So the only thing left was the axles, transfer case, and transmission. It has a BD performance tranny and after shutting off the engine and putting it in neutral and coasting back down from 80 it still shook at 70 and 35 - now i knew it was drive train.

Pulled the transfer case out opened it up and WOW it was full of chewed up gasket maker. The sump in the bottom of the case was nearly plugged solid, there were bits of the crap in the bearings and planetary gears. Cleaned every thing out, put in a chain while it was open put it back together and Vibration was gone!!! If you are having a vibration and ALL u-joints are good FRONT and REAR including front axle joints then this might help. You can pull the rear of the case off to inspect without removing the whole transfer case.

Was a very weird problem. A few weeks later the R/FRT axle shaft u-joint went bad and had the almost same identical feeling vib that felt like it was going through the frame. Best wishes to anyone who has had this problem and has no hair left!!

 

Very good info, as I have the same vibration under load and @ highway speeds in my '98. I know I have a bad left front u joint as it fights the steering in 4x4. I'm changing both fronts tomm. and we'll go from there!!!!!!

 

Is your truck a LWB?

 

It is the cowboy limosine i'm told-yes long bed extended cab.