2016 Kenworth T680 Front End Shakes at 50mph!

See if you can get someone to pace you in another vehicle and look at both your wheel and hub assembly’s on the steer for movement while at that speed.
See what type of movement it is in relation to the axle parts.
We’ve all seen those trucks going down the highway with a front wheel shaking so violently the fender and hood is hanging on for dear life. Makes you wonder how the driver doesn’t pass out from keeping it going with that death grip on the wheel.

 

10-4. What kind of movement did you see?
Bounce? Right to left, in and out? Oscillating? In and out from top to bottom?

 

"Got the alignment and tires balanced by dealer. Alignment and balancing didn't fixed the shaking."

"Some" Dealers only know how to do "basic stuff" and sometimes that's problematic.

I would NOT go back to that "shop".

I will venture a Guess at NEW SUSPENSION PARTS, possibly Bearings too as well completely checking Rear Suspension and Components.

Cab Structural Integrity Test - AMPLIFIED.
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I've driven a few trucks, not far, with those problems.

 

I know they have been having a few problems with tie rod and king pin quality the last few years. Seems the new school engineers didn’t like the fact that the older designs were stronger and lasted forever so they fixed that pesky little problem.

 

Yep lots of things many suggestions all good, king pins, and tie rod although not sure it that'll actually cause it to shake? Should have problems steering if that was the case, does it only shake at high speeds? I assume you've done the obvious and checked to make sure the wheel nuts are tight? That's the first thing I'd check anyway, have any of the counter weights they've used to balance the wheels fallen off as that will make it shack again, are you the only one driving it? As somebody may have hit something with the rim/ wheel these are all possibilities. How is your steering wheel? Is it not sitting in the correct position at 2: 45?