I own an 05 four door short bed. Yes, it came with the 70 mph vibration. In short there were two sources of vibration. First, the muffler and exaust system was put together with extreame pressure on the mounting brackets (hangers) transmitting vibration to the frame. I loosened the muffler clamps and beat the pipe into the muffler until the pressure was off of the hangers. Next I balanced the rear driveshaft, and all the vibration is gone. I determined where the vibration was being generated using equipment that measures vibration in big industrial motors. I was able to determine the frequency of the vibtations and by moving sensors around I was able to locate the source. I balanced the rear driveshaft with two stainless steel 4 inch hose clamps. I chased the vibration all the way to the middle of the driveshaft. Need more info, just ask.

 

What procedure did you use to balance the driveshaft?

 

Rod: can you post some pictures also did you get rid of the droning sound that was in conjunction with the vibe?

 

Glad you fixed it but that's the normal 2100rpm engine drone. They all have it. My '95, '98, '01.5 and '03 had it. The exhaust can amplify it if it's in a twist as yours apparently was. My previous Cummins powered Rams all smoothed out at around 60k. My '03 was not motor vibrations. It would do it with the motor off. We're talking about two different vibrations. I wish all mine was was the normal 2100rpm engine buzz. The '98 was the first year of the hydro boost brake booster. That's when the normal engine buzz found it's way into the steering wheel. Mine was not in the steering wheel. It was in the seats and floorboard. It would rattle change in the ashtray at it's worst and one trip didn't do it at all. I haven't a clue but when it was doing it I could shut the motor off in neutral and it was still there.

 

The two frequencies were very close. Starting at 68 mph it set up a harmonic. By relieving the tension on the muffler brakets it reduced the vibration induced into the frame. I balanced the drive shaft by starting at the balancing wheel at the front of the rear driveshaft. I took two ss hose clamps and tightened them at a 10:00 / 2:00 position. I maintained this offset but moved both clamps an inch at a time for the full 360 degrees. The vibration was worse in every position than it was without the clamps on it. But the vibration sensing equipment I used indicated it was coming from the drive shaft. The sensor was fastened to the transfer case where the spline enters it. I did the same procedure in the center of the drive shaft and found a sweet spot which lessened the vibration. Then I moved the head of the clamps closer and further apart until the vibration was eliminated. I ended up with the heads of the hose clamps about 2" apart. The instruments and the seat of my pants told me the vibration was gone. I will get you the name and model # of the vibration instrument later, I knew I should have written it down.

 

Sounds like you found a great fix for this. 68mph is exactly when mine would kick in.

Jamie

 

I stand corrected. I should have tried that. I read about that method in the '95 Dodge Cummins shop manual I bought with my '95. I had my '03 on jack stands and could feel the vibration with the rears off the ground running 68mph. I could have possibly solved my vibration right there in the carport. And... I'd still have my '03 Cummins powered Ram. Now I'll never know. To think the answer might have been right there in front of me.

 

wow, I was just telling my wife yesterday that the truck was not shifting well from a stop into 2nd and going from 4th to 3rd is tough. made an appontment with the dealer. was also wondering if i got the vibe I have 5300 miles on my 3500 dually and about 4 days ago my truck started vibrating from 70 to 75 feels like a tire out of balance. I heard that if the truck didnt have it to start that it wouldnt get it and that duallys werent prone to get it. could it be a tire or could i have the dreaded vibe?