Eaton 18 speed Driveline vibration

I would start with checking driveshafts

 

Used a truck years ago, that had a bad driveline vibration so bad by the end of my shift, I was nearly suffering from vertigo. Wrote it up numerous times. Guys that slip seated refused to write it up, so nothing was done. One morning city driver got in, put truck it gear, and BAM! the power divider took a dump. Got truck back from shop a couple weeks later, and miraculously that vibration unexplainably was gone. Told the asswipe dispatcher, maybe next time you’ll listen.

 

Most vibrations are from driveline problems or tires. I would start by checking u-joints and yolks. When yolks go bad the u-joint holes become egg-shaped.

 

It sounds like a problem with the rear ends. If you aren't having issues shifting and its staying in gear then I would rule out the tranny. I would check the entire drive line, every U-joint and yoke, hanger bearings etc. Having said that I would drop the oil in both axles checking for metal, if there isn't anything there then maybe drop the tranny oil.

 

first check Ujoints, steady bearings , slip joints and ride height. These are the most often causes of vibration under load. The gear you are pulling in can amplify or minimize the vibration.

 

I would start with looking at your tires and seeing if it's possible that they could be making a problem.

One time I had a vibration in my truck and I swapped around the tires and after that I had no more problems. That was only happening in a particular gear or two like you're saying.

The other thing is that if your rear has a lot of slop in it, and what I mean by slop is up and down slop, then your bearing needs to be reshimmed before it gets destroyed.