Vibration

[Waterloo]

What make, model, year and mileage?

The shocks could, any odd tire wear? Inspect the u joints? Pin bushings and torque rod bushings up between the frame rails? Depending upon the mileage of the truck, it may just be time for new u joints and bushings, around 800,000 is their life span. If the truck hauls heavy the majority of the time, 600,000 to 700,000 miles to beat a catastrophic failure like Rawze had up in Utah area, it was ugly, and very expensive. Nothing to ignore.

I replaced all of the above at roughly 750,000 miles. The u joints were shot, but they took grease. So a simple visual on those is not always going to be accurate.

I don't haul heavy and put few miles on the truck, so I swap out shocks every two years. Many guys replace shocks yearly, depending on what they haul.

Also, on Merritor rear ends there is a crush washer, it hides behind the yoke in the front differential, it needs to be replaced any time the drive shaft and yoke is removed, one time use. If you don't replace, there will be some play in the yoke/driveshaft, that could cause a vibration. No clue if the other rear end guys use the same setup with the crush washer. If that is the case, Fleetpride is the best place to purchase, half the price of the dealer.

Could be that crush washer from when you installed the new carrier bearing. Not replacing that crush washer can take out your carrier bearing. That is how I discovered it.

Just a few things off the top of my head.