Hmmmm, Mine is exactly the same as yours at the same exact speeds!
Time to pull the rear drive shaft out?

 

Excessive pinion angle is a well-known issue with our 2-piece propeller shafts, especially with a lift, and even w/o if you drive unloaded.

Dodge designed the rear suspension to carry a lot of weight, so empty - the bed (with carrier bearing attached) sits too high over the axle... same result if you lift the rear.

Installing a carrier bearing spacer is a cheap and easy fix for the driveline angle-induced vibration.

 

I could see that happening but mine is a one peice driveshaft with the slip yolk at the transfer case, no carrier bearing and no lift in the rearend, just a leveling kit in the front. Still love the truck, this is just a major peave (peeve?) of mine so I would like to get it fixed. My Chevy did this also. 3/4 ton 4x4. I had the driveshaft checked,new u-joints, new bushings in transfer case, changed pinion angle a few different times, checked axles for true, balanced wheels and tires multiple different places and even changed wheels and tires, alignments....thats why I sold it. It was bad enough at the end that my mirrors would go blurry. Made me dislike GM even more than before.

 

There is another obvious way to narrow down the source of vibrations. If you have access to a lift, put the truck up in the air and remove the front shaft. Support the rear drive line so that ride height and therefore pinion angle are what they would be normally and run it up to speed. If it still vibrates that eliminated the front end issue and your expensive replacement hubs. The same can be done by removing the rear shaft to isolate the front, although you will have to get a yoke to stick in the back of the transmission to plug the hole.

 

What does a driveline shop charge to balance your driveshaft to very close "standards"? I would like to do that but Im sure it wouldnt be cheap. Here I am talking about cheap again. Promise it wont happen again...haha. I have a Bronco habit to feed.

 

Couldn't really say how much because he didn't charge me at all for the second go around. I had originally purchased the shaft from him so he took the time to fix it for free once I took him for a ride in my truck. Figure he spent at least two hours at the balancing so at my rates that would be $140. I jus threw him $20 bucks for lunch and a handshake.

 

I too found out the wonderful quality of the drive shafts that are under the dodge trucks.

https://www.dieseltruckresource.com/...86#post1884786

Not only did I have to replace the two rear joints on my drive line, when the shop that did my ujoint job also got the shafts 180 out of phase. The vibration was so bad that I couldn't stand it any more and I took it to a "real" driveline shop that could balance the drive line.

Get this, the "real" shop was able to get the shaft assembly to balance, but the shaft had .050" run out at the carrier bearing on the stock shaft!!!! No wonder my truck spit it's u-joints at 40k mi. I ended up having them fabricate a brand new rear section with run out at .002".

What ticks me off is that I ended up dumping almost $500 into the drive line by the time labor and parts were accounted for at both shops.

As usual, DCX had their heads in the sand for this first and definately the last time Dodge truck owner.

Moral of the story is don't take your truck into a shop unless they can balance and repair drivelines.

 

I just went on a 400 mile drive with my truck and I noticed that when I go uphill and maintain a speed, the vibration gets worse. The truck only has 13000 miles on it. Im wondering if my pinion angle is changing due to more torque at the wheels when going up a long hill.