It looks like D60 was right about it not being a driveline issue.
I replaced the control arms, and that seems to have made a big difference. The shaking has largely abated - I can confidently drive at 60-70 mph again. The truck still rides like ****, but it never was very smooth, and a lot of...
It seems that lots of Ram owners deal with this same thing, whether gas or diesel: https://www.cumminsforum.com/threads/vibration-at-highway-speeds-65-70mph.475016/?nested_view=1&sortby=oldest
I would love to have a shop with one of those vibration analyzer systems do an analysis, I just have...
I replaced the 3rd U-joint along with the slip yoke bushing and seal. Truck feels tighter/smoother, except it still shakes/bucks at certain speeds (around 45 and 65 mph). So the problem lies elsewhere.
I replaced 2 out of the 3 U-joints in the main drive shaft (I boogered up a bearing cap on the 3rd new joint, gotta get another one). It made quite a difference. The old joints were definitely bad - there were grooves worn into the machined ends where the needle bearings ride. But there was no...
I got a Harbor Freight clamping dial indicator, measured runout at around 0.004" on both rear axle flanges, so I no longer suspect a bent axle shaft. At least the leaking axle seal has now been replaced. I also replaced the carrier bearing on the driveshaft, which did not solve anything. Gonna...
Did you ever verify where the wobble is coming from? I have an '06 Ram 2500 with the same 10.5" AAM rear, and I have the same problem: wobble in the left rear wheel assembly. This wheel overheated badly years ago due to a stuck caliper (which was then replaced) but the problem isn't in the rotor...